STATE OF COLORADO
 

Bill Ritter, Jr., Governor 

James B. Martin, Executive Director 

Dedicated to protecting and improving the health and environment of the people of Colorado 

4300 Cherry Creek Dr. S. Laboratory Services Division 

Denver, Colorado 80246-1530 8100 Lowry Blvd. 

Phone (303) 692-2000 Denver, Colorado 80230-6928 

TOO Line (303) 691-7700 (303) 692-3090 Colorado Department Located in Glendale, Colorado of Public Health
 

http://www.cdphe.state.co.us and Environment
 

June 18, 2009 

Carol Rushin 

Acting Regional Administrator 

US EPA Region VIII 

1595 Wynkoop Street 

Denver, CO 80202-1129 

Dear Ms. Rushin: 

The Interstate Air Pollutant Transport State Implementation Plan (SIP) is submitted to EPA for final approval and
 

incorporation into the Colorado State Implementation Plan. Two copies of the materials needed for your review
 

of each action are included with this letter.
 

On December 12,2008, the Colorado Air Quality Control Commission (AQCC) adopted a proposal to revise the
 

ozone interstate transport element of the State Implementation Plan to address outstanding issues that EPA had
 

identified with the original plan adopted by the AQCC in February 2007. This plan for the 1997 eight-hour
 

Ozone Standard supersedes the first two elements ofthe SIP adopted by the AQCC and submitted June 11,2008.
 

The Interstate Transport SIP for the 1997 eight-hour Ozone Standard submitted with this letter addresses part of
 

the CAA Section II 0(a)(2)(D)(i) provisions. The attached SIP addresses the elements covered by CAA Section
 

IIO(a)(2)(D)(i)(I): significant contribution to nonattainment and interference with maintenance in another state.
 

We understand that EPA intends to issue new guidance addressing the two elements, PSD and visibility, covered
 

by Section 1IO(a)(2)(D)(i)(II). Upon EPA's issuance of the new guidance, the state will prepare the remainder of
 

the SIP.
 

We look forward to your timely review and approval ofthis request. The AQCC office may submit any
 

additional technical support documentation or information that you may need for review directly to the EPA.
 

Should there be any questions regarding these materials, please contact the AQCC office at 303-692-3478. Thank
 

you.
 

Sincerely,
 

RECEIVED
 

JUN 23 2C~9

USEPARNS OFFICE
 
Interstate Air Pollutant Transport
 

State Implementation Plan
 

ADMINISTRATIVE MATERIALS 

Copies of the following administrative materials are included in this submittal ofrevisions to 

Interstate Air Pollutant Transport State Implementation Plan. Hearing held on December 11 

& 12,2008. 

•	 Hearing Notice and Proposed Language as Published in the CCR 

•	 Meeting Agenda where Public Hearing Occurred and Notice published in the Legal 

Ads of the Denver Post 

•	 Procedural Documents of the Commission (this includes the Agenda Item Control 

Sheet, the Memorandum ofNotice, the Economic Impact Analysis) 

•	 Parties Hearing Documents (this includes a list of the parties, the parties prehearing 

statements and rebuttal statements, and any orders by the Commission - - do not 

include all the attachments from the parties) 

•	 EPA Comments 

•	 Public Comments 

•	 Adopted Statement of Basis, Specific Statutory Authority and Purpose 

•	 Adopted Language by the Commission (in redline & footer noting adoption date and 

page numbers) 

•	 Final Adoption Notice 

•	 Opinion of the Attorney General 

•	 Regulation as published in the CCR (this is the version that is published by Lexis 

Nexis) 
Hearing Notice and Proposed Language
 

as Published in the CCR
 
STATE OF COLORADO
 

Bill Ritter, Jr., Governor
 

James B. Martin; Executive Director
 

Dedicated to protecting and improving the health and environment of the people of Colorado 

COLORADO AIR QUALITY CONTROL COMMISSION
 

httpJ:wv.w.cdphe.state.co.us
 

EDO-AQCC-A5
 

4300 Cherry Creek Drive South
 

Denver, Co lorado 80246-\530
 

Phone (303)692-3100 Colorado Department 

Fax (303) 691-7702 of Public Health TOO (303) 691-7700 and Environment 

NOTICE OF PUBLIC RULEMAKING HEARING 

BEFORE THE 

COLORADO AIR QUALITY CONTROL COMMISSION 

Regarding proposed revisions to:
 

Ambient Air Quality Standards Regulation,
 

Regulation Numbers 3, 7, and 11
 

for the
 

Denver Metropolitan &North Front Range Area Ozone Action Plan
 

SUBJECT: 

The Air Quality Control Commission will consider a proposal from the Denver Metropolitan 

Area's Regional Air Quality Council, the North Front Range Transportation & Air Quality 

Planning Council and the Colorado Department of Public Health and Environment Air Pollution 

Control Division to adopt an ozone action plan for the Denver Metropolitan and North Front 

Range 8-hour ozone nonattainment area. The ozone action plan proposes to reduce ambient 

ozone concentrations in the nine county area to meet the requirements of the national ambient air 

quality standard for ozone averaged over an 8-hour period and to address the directive of 

Governor Ritter to further reduce ambient ozone concentrations. The ozone action plan proposes 

to make revisions to the Ambient Air Quality Standards regulation to include mobile source 

emission budgets for the 8-hour ozone nonattainment area for purposes of conducting 

transportation conformity analyses. The ozone action plan proposes to revise Regulation 

Number 3 and Regulation Number 7 to include additional emission reduction, record keeping 

and emission reporting requirements for stationary sources of volatile organic compounds and 

for oxides of nitrogen in the nonattainment area and on a statewide basis. The proposed ozone 

action plan would make revisions to Regulation Number 11 to require the implementation of a 

vehicle emissions inspection program in the North Front Range portion of the 8-hour ozone 

nonattainment area and would include a March 2008 action of the Commission to revise the 

tailpipe emission standards for the program in the State Implementation Plan to make it federally 

enforceable. The ozone action plan proposes to include some of the proposed new requirements 

in the federally enforceable State Implementation Plan and would retain some of the new 

requirements exclusively for state enforcement only. The ozone action plan proposes to modify 

the provisions of the Interstate Air Pollutant Transport State Implementation Plan element 

adopted by the Commission in February 2007, by noting that the proposed maintenance plan 

would prevent the Colorado Front Range from contributing significantly to ozone non-attainment 

Page 1 of4 
or interfere with long-term maintenance ofthe national ozone standard in any other state. The 

ozone action plan proposes to make typographical, grammatical and formatting revisions to the 

above identified regulation's. 

FEDERAL REQUIREMENTS: 

The federal act requires the adoption of a State Implementation Plan element with accompanying 

rules and requirements to demonstrate compliance with the National Ambient Air Quality 

Standard for ozone averaged over an 8-hour period and the associated technical support 

documentation to make that demonstration. A proposed Statement of Basis, Specific Statutory 

Authority, and Purpose and a regulatory analysis (if one has been requested) will be available for 

inspection no later than five (5) days prior to the hearing. The language of the proposed rule 

revisions is attached to and made a part ofthis notice. 

HEARING SCHEDULE: 

DATE: December 11,2008 

TIME: 9:00 AM 

PLACE: Colorado Department of Public Health & Environment 

4300 Cherry Creek Drive South, Sabin Conference Room 

Denver, Colorado 80246 

The hearing may be continued at such places and time as the Commission may announce. 

Interested parties may contact the Commission Office at 303-692-3476 to confirm meeting dates 

and times. 

PUBLIC COMMENT: 

The Commission encourages all interested persons to provide their views either orally at the 

hearing or in writing prior to or at the hearing. The Commission especially solicits comments 

and analyses from persons who will incur directly some cost or benefit from the proposed 

revisions. Public testimony will be taken as close to the start of the hearing as possible and 

during the hearing as necessary. Written and/or electronic submissions prior to the hearing are 

requested to allow review prior to presentation at the hearing. Written and/or electronic 

submissions should be mailed to the Commission Office at least 14 days prior to the hearing. 

PARTY STATUS: 

In order to obtain party status at the hearing, compliance with several requirements as defined in 

the Commissions Procedural Rules is necessary. A petition for party status must be filed by 

electronic mail with the Office of the Air Quality Control Commission no later than close of 

business on October 15, 2008. The petition must: 1) identifY the applicant; 2) provide the name, 

address, telephone andfacsimile numbers, and email address ofthe applicants representative; 

and 3) briefly summarize what, ifany, policy, factual, and legal issues the applicant has with the 

proposal(s) as ofthe time offiling the application. Electronically mailed copies must also be 

received, by this same date, by the Division staff person and the Assistant Attorneys General 

representing the Division and the Commission identified below. Any person may petition the 

Commission to file documents in paper copy format if they are unable for any reason to not 

comply with the requirements of 1.3.8(2) of the Commissions Procedural Rules. An original and 

a specified number of paper copies must be filed in the Office of the Air Quality Control 

Page 2 of4 
Commission, Colorado Department of Public Health and Environment, 4300 Cherry Creek Drive 

South, Denver, Colorado 80246. 

Individuals may also obtain party status through the submittal of an initial alternative rule to the 

proposed rule. The submittal of an alternative proposal must be accompanied by an electronic 

copy of the initial alternative proposed rule and all other associated documents as required by the 

Commission's procedural rules and must be filed by electronic mail with the Office of the 

Commission by the date specified for party status requests. Initial alternative rules must also be 

filed by electronic mail with the Division staff person and with each of the Assistant Attorneys 

General. 

Air Quality Control Commission Air Pollution Control Division 

Theresa L. Martin Mike Silverstein 

EDO-AQCC-A5 APCD-Bl 

4300 Cherry Creek Drive South 4300 Cherry Creek Drive South 

Denver, CO 80246 Denver, CO 80246 

Theresa.Martinrmstate.co.us Mike.Silverstein(a),state.co.us 

Jerry Goad Thomas Roan 

Attorney for the Commission Attorney for the Division 

Attorney General's Office Attorney General's Office 

1525 Sherman St., 5th Floor 1525 Sherman St., 5th Floor 

Denver, CO 80203 Denver, CO 80203 

Jerr)'.Goad(a),state.co.us Tom.Roanrmstate.co.us 

Requests received beyond the above stated deadline shall only be considered upon a written 

motion for good cause shown. The Commission reserves the right to deny party status to anyone 

that does not comply with the Commission's procedural rules. 

STATUS CONFERENCE: 

A status conference will be held October 17,2008 at 9:00 a.m., at the Department of Public 

Health and Environment to ascertain and discuss the issues involved, and to ensure that parties 

are making all necessary efforts to discuss and resolve such issues prior to the submission of 

prehearing statements. Attendance at this status conference is mandatory for anyone who has 

requested party status. 

PREHEARING CONFERENCEIPREHEARING STATEMENTS: 

Attendance at the prehearing conference is mandatory for all parties to this hearing. A 

prehearing conference will be held November 17,2008 at 1:00 p.m. in the Commission Offices 

at 4300 Cherry Creek Drive South, Denver. All parties must submit by electronic mail a 

prehearing statement to the Commission Office by close of business November 13,2008. In 

addition, electronically mailed copies of these documents must be delivered by that date to all 

persons who have requested party status. A copy ofthe prehearing statement must also be 

electronically mailed to the Division point of contact and each ofthe Assistant Attorney's 

General identified above by close of business November 13, 2008. Any exhibit included in the 

prehearing statements will be electronically mailed to individual Commissioners for review prior 

Page 3 of4 
to the hearing, provided the party files electronic copies of such exhibit. Rebuttals to the
 

prehearing statement may be submitted to the Commission Office and all other parties by close
 

of business November 25, 2008.
 

EXCEPTIONS TO FILE DOCUMENTS BY ELECTRONIC MAIL
 

The Commission's Procedural Rules provide for an exception to file documents by electronic
 

mail. If granted an exception to electronic filing pursuant to the provisions of 1.3.8(3) of the
 

Commissions Procedural Rules, the applicant for party status shall file an original and fifteen
 

copies of the prehearing statement in the Office of the Air Quality Control Commission, and
 

shall also deliver copies to each other party, applicant for party status, the Assistant Attorneys
 

General representing the Commission and Division, and the Division staff person for the
 

proceedings, by electronic mail or as otherwise provided by the exception granted under
 

Subsection 1.3.8(3), by that same day.
 

STATUTORY AUTHORITY FOR THE COMMISSION'S ACTIONS:
 

The Commission promulgates these regulatory changes pursuant to its authority to 25-7-101, 25­


7-103,25-7-105.1,25-7-109,25-7-110.5,25-7-110.8, 25-7-301 and 42-4-306, C.R.S. The
 

rulemaking hearing will be conducted in accordance with sections 24-4-103 and 25-7-110,
 

C.R.S., as amended, the Procedural Rules of the Commission and as otherwise stated in this
 

notice. This list of statutory authority is not intended as an exhaustive list of the Commission's
 

statutory authority to act in this matter.
 

Dated this 25th day of September 2008 at Denver, Colorado
 

Colorado Air Quality Control Commission 

Douglas A. Lempke, Administrator 

Page 4 of4 
Meeting Agenda where Public Hearing Occurred and
 

Notice published in the Legal Ads ofthe Denver Post
 
STATE OF COLORADO
 

Bill Ritter, Jr, Governor 

James B. Martin, Executive Director 

COLORADO AIR QUALITY CONTROL COMMISSION 

http:·wwwcdphe.state.co.lls 

4300 Cherry Creek Drive South 

OED-OLRA-A5 

Denver, Colorado 80246~1530 

Phone (303) 692-3100 Colorado Department 

Fax (303) 691-7702 of Public Health TOO (303) 691-7700 and Environment 

Notice of Meeting and Agenda
 

Air Quality Control Commission
 

December 11-13 & 19,2008 

Colorado Department of Public Health & Environment
 

4300 Cherry Creek Drive South, Sabin Room
 

Denver, Colorado
 

Call to Order: 

Public Comment: 

Agenda Review: 

DECEMBER 11-13, 2008 

9:00 AM 

Determination of a Quorum 

The public is invited to comment on any air pollution issue not on 

the agenda. The Commission will not take action on issues 

discussed under this agenda item today; however, items may be 

scheduled for further discussion or action. 

The Commission Administrator will review the meeting agenda 

and discuss any proposed revisions to the agenda for the 

Commission's consideration. 
RULEMAKING HEARING 

1.	 Denver Metropolitan and North Front Range Area Ozone Action Plan 

(l0.5 hours presentation, 11 hours discussion) 

The Regional Air Quality Council, the North Front Range Transportation and Air Quality 

Planning Council and the Division will present to the Commission a proposed 8-hour ozone 

attainment plan and accompanying regulations; Regulation Numbers 3, 7, 11 and the 

Ambient Standards Regulation, to revise the State Implementation Plan as well as state only 

regulatory requirements to reduce ozone precursor emissions and demonstrate compliance 

with the 8-hour ozone National Ambient Air Quality Standards and to address the 

September 2007 directive of the Governor to work toward attainment of the newly revised 

8-hour ozone standard. 

DECEMBER 19, 2008 

9:00 AM 

Call to Order:	 Determination of a Quorum 

Approval of Minutes:	 Review/Approval of the October 16,2008 and November 20 & 21, 

2008 meeting minutes of the Air Quality Control Commission. 

Public Comment:	 The public is invited to comment on any air pollution issue not on 

the agenda. The Commission will not take action on issues 

discussed under this agenda item today; however, items may be 

scheduled for further discussion or action. 

Agenda Review:	 The Commission Administrator will review the meeting agenda 

and discuss any proposed revisions to the agenda for the 

Commission's consideration. 

PUBLIC HEARING 

1.	 Denver Regional Council of Governments (DRCOG) Conformity 

(20 minutes presentation, 20 minutes discussion) 

The DRCOG will present to the Commission its anticipated Transportation Conformity 

findings regarding the 2035 Regional Transportation Plan and 2008/2013 TIP. 

RULEMAKING HEARING 

2.	 Regulation Numbers 3 - BART 

(110 minutes presentation, 60 minutes discussion) 

The Commission will hold a public rulemaking hearing to consider a proposal from the 

Division to revise the regulation by adding Best Available Retrofit Technology (BART) 

Requirements to the rule for the Colorado Springs Utilities Martin Drake units 5, 6 and 7 

and the CEMEX Lyons Cement plant regarding emission controls for sulfur oxides, nitrogen 

oxides, and particulates. This rulemaking activity will also be an update to the State 

Implementation Plan for Regional haze. 

2 
3.	 Regulation Number 9: Smoke Management Distribution of Cost Update 

(30 minutes presentation, 30 minutes discussion)
 

The Division will present to the Commission proposed changes to Regulation Number 9,
 

Appendix C regarding the distribution of the program's cost to its permittees based on recent
 

activity data.
 

BRIEFINGS, DISCUSSIONS AND REpORTS 

4.	 Commissioner Informational Items 

Commissioners will discuss among themselves activities that they have participated in over 

the past month that they believe other Commissioners and/or members of the public may be 

interested in hearing about. 

5.	 Division Director's Report - Paul Tourangeau 

Monthly activities report 

6.	 Attorney General's Report - Jerry Goad 

Update of any recent court actions on air quality issues 

7.	 Administrator's Report - Doug Lempke 

January meeting agenda items review 

Adjourn 

3
 
The Denver Newspaper Agency 

DENVER,CO 

PUBLISHER'S AFFIDAVIT 

City and County of Denver, 

STATE OF COLORADO, SS. 

.... . ... .Jean Birch being of lawful 

age and being first duly awom upon oath, depo.e. and .ay.: 

That hel.h.l. the Legal Advertising Reviewer 

Of Th. D.nv.r N.wspaper Ag.ncy, publl.h.r of the D.nv.r Po.t and 

Rocky Mountain N.w., dally n.wspapers of g.n.ral Circulation publl.hed 

and prlnt.d In whol. or In part In D.nv.r, In the County of D.nv.r and 

Stat. of Colorado, and that .ald n.wspap.r wa. Prior to and during 

all the tim. h.r.lnaft.r m.ntlon.d duly quallfl.d For the publication of 

I••al notlc•• and adv.rtl••m.nts within the M.anlng of an Act of the 

O.n.ral As••mbly of the Stat. of Colorado, 

Approved April 7, 1'21, .. am.nd.d and approv.d March 30, 1e23; 

And .. am.nd.d and approv.d March 5, 1e35, .ntltled -An Act 

Conc.mlne L.eal Notlc••, Adv.rtI••m.nts and Publication. and the 

F••• of print.... and publl.h.... th....of, and to ...p.al all acts and parte 

Of acts In conflict with the provl.lon of thl. Act- and am.ndm.nts 

Th....to: 

That the notlc., of which the ann.x.d I. a true copy, wa. publl.h.d In 

Th••ald n.w~:rto wit! (dat•• of publication) 

............./l,;1~ .~f./..?:zb?:5: .
 

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.................. ~~.~ . Slenatur. 

Sub.crlb.d and .wom to b.for. m. thl•••••• 21 ••••• day 

Of ••• November ••• A.D. 200.. • 

.... ..~.~tJ. ...J.-.~. p( . Notary Public. 

My comml••lon .xplre•••••• S.pt.mb.r e, 2009 ••••• 
Procedural Documents of the Commission 

- Agenda Item Control Sheet
 

- Memorandum of Notice
 

- Economic Impact Analysis (initial and final)
 

- Proposed SIP (narrative)
 
COLORADO AIR QUALITY CONTROL COMMISSION
 

AGENDA ITEM CONTROL SHEET
 

Item Title: Revisions to Regulation Number 7 and Regulation Number 3. Parts A. Band C for 

Incorporation into the State Implementation Plan (SIP) 

Meeting date:__.;::;S=ea:.;pt=e..:.:.m.:.:;:b"""e-,-r~1.:.8!r...::2=0:..;:0:.=8

TYPES OF ACTION 

NON-HEARING ACTIONS REQUEST FOR HEARING HEARING 

Administrative Public Rulemaking _ Public Rulemaking -

_ Briefing Informational Informational - -

_ Policy 

_Area Designations 

RECOMMENDED ACTION 

_Adoption lApproval Denial -

MOTION 

--X Required Attached _ Not applicable -

STATUTORY AUTHORITY 

General Specific __.....;X:..:, 

EPA SUBMITTAL 

Is this issue considered a SIP revision? Yes X No _ ---=-~

Which SIP? Ozone Reporting and Permitting Elements 

Date of EPA submission deadline: July 2009 

Proposed Regulations 3 and 7 sip Revisions 1 

9/2/08 
ISSUE: The Colorado Department of Public Health and Environment, Air Pollution Control 

Division ("Division"), in coordination with the Regional Air Quality Council (RAQC) and the 

Northern Front Range Metropolitan Planning Organization (NFRMPO) as the Lead 

Planning Agencies, requests that the Colorado Air Quality Control Commission 

("Commission") revise the requirements set forth in Regulation Number 7 and Regulation 

Number 3, to address ozone formation in the 8-hour ozone non-attainment area (a.k.a. the 

9-county Denver Metro Area/North Front Range (DMAIMFR) Non-Attainment Area (NM)) 

and state-wide. Specifically, the Division's proposed revisions serve to reduce volatile 

organic compound (VOC) emissions, an ozone precursor, and thus reduce ozone 

concentrations in ambient air. These revisions are necessary to ensure attainment with the 

current 8-Hour Ozone National Ambient Air Quality Standard (NMQS) set at 0.08 parts per 

million (ppm), and to otherwise achieve ozone reductions in light of both the new 8-hour 

Ozone NMQS set at 0.075 ppm and the Governor's July 27,2007 directive to proactively 

and pragmatically reduce ozone levels. Also, the Division is proposing revisions to 

Regulation Number 3 to revise Air Pollution Emission Notice (APEN) reporting 

requirements to improve the Division's emissions inventory, to facilitate planning for 

development of additional emissions reductions strategies that may be needed to meet the 

Environmental Protection Agency's new ozone NMQS, that lowers the standard from 0.08 

ppm to 0.075 ppm. Specifically, the Division requests that the Commission set for public 

hearing the proposed revisions to Regulation 7 as follows: 

•	 change the title to identify NOx in addition to VOC as an ozone precursor, 

•	 modify the emission and add monitoring control requirements applicable to 

condensate storage tanks at oil and gas exploration and production operations, 

natural gas compressor stations and natural gas drip stations located in the 8-Hour 

Ozone Non-attainment Area (Regulation 7, Section XII), 

•	 set new emission control requirements for pneumatic controllers associated with oil 

and gas operations located in the 8-Hour Ozone Non-attainment Area (Regulation 7, 

Section XIII), 

•	 expand the applicability of Reasonably Available Control Technology (RACT) 

requirements to existing, new and modified sources in ozone non-attainment areas 

outside of the historic 1-hour Ozone Non-attainment or attainment/maintenance area 

(Regulation 7, Sections I-XVIII), 

•	 make clarifications or corrections as identified (Outline of Regulation and Sections II, 

VI, VII), and 

•	 make typographical, grammatical and formatting changes, as necessary. 

Additionally, the Division requests that the Commission adopt proposed revisions to 

Regulation 3 to revise APEN reporting exemptions for specific source categories 

(Regulation 3, Part A, Section 11.0., Part B, Section 11.0., and Part C, Section II.E.). 

I. Background 

Proposed Regulations 3 and 7 SIP Revisions 

9/2/08 

2 
State and regional agencies in the Denver metropolitan area entered into a voluntary 

agreement with the U.S. Environmental Protection Agency (EPA) in December 2002 

that laid out a process for achieving attainment with EPA's 1997 8-hour National 

Ambient Air Quality Standard (NAAQS) for ozone of 0.08 ppm in an expeditious 

manner. Called an Early Action Compact for Ozone (lithe EAC"), the agreement set 

forth a schedule for the development of technical information and the adoption and 

implementation of the necessary control measures into the state implementation plan 

(SIP) in order to comply with the 0.08 ppm 8-hour standard by December 31, 2007 and 

maintain the standard beyond that date. The EAC Ozone Action Plan (SIP) was 

submitted to EPA summer 2004. EPA promulgated approval of the Ozone Action Plan 

in the Federal Register (Vol. 70, Number 94, May 17, 2005). A revision to the Ozone 

Action Plan to preserve the reductions estimated in the original plan was approved by 

the Air Quality Control Commission on December 17, 2006 and the Colorado State 

Legislature in spring 2007, and submitted to the EPA in February 2008. 

Based on the 2001-2003 design values, the DMAlNFR 8-hour ozone control area 

violated the 8-hour ozone standard at three monitors. In April 2004, EPA designated 

and classified areas of the country that violated the 8-hour standard. At that time, based 

on the EAC, the EPA deferred a DMAlNFR non-attainment area designation. 

The DMAlNFR deferred non-attainment area failed to achieve the standard due to high 

readings in July 2007 which resulted in a 3 year (2005-2007) Design Value of 0.08 ppm 

at one monitor (Rocky Flats North) which violated the 8-hour ozone NAAQS. 

The EPA's deferral of a nonattainment designation for the area expired on November 

20, 2007, signifying that the area is now considered nonattainment, or in violation of the 

1997 eight-hour ozone NAAQS of 0.08 ppm for ground level ozone. The DMAlNRFA 

includes all of Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, and Jefferson 

Counties as well as portions of Larimer and Weld Counties. This area is now known as 

the Denver Metro Area/North Front Range Non-Attainment Area. 

Pursuant to the Federal Clean Air Act, Colorado must prepare and submit to EPA a 

State Implementation Plan (SIP) no later than June 30, 2009. This plan must propose 

measures designed to reduce ground level ozone as necessary. These emission 

reductions must be sufficient to ensure that ozone is reduced to below the eight-hour 

NAAQS no later than 2010. If Colorado fails to submit a SIP by the deadline, the Clean 

Air Act mandates that the EPA prepare and implement a Federal Implementation Plan. 

The Colorado General Assembly has mandated that the Commission adopt such 

measures as are necessary to ensure compliance with the NAAQS. The Commission 

has adopted these rules to carry out this mandate. 

Photochemical grid dispersion modeling indicates that without further emission controls, 

Colorado will attain the eight hour standard by 2010. The dispersion modeling reflects 

that Colorado would attain the standard by a narrow margin - within 0.001 ppm on a 

standard of 0.08 ppb. Photochemical dispersion modeling analysis is the primary tool 

Proposed Regulations 3 and 7 SIP Revisions 

9/2/08 

3 
used to assess present and future air quality trends, and is required for EPA to approve 

the state attainment demonstration in the SIP. dispersion modeling results have an 

inherent level of uncertainty, as recognized in EPA guidance, and it is appropriate for a 

state to use other tools at its disposal, including further control measures, to address 

and mitigate any uncertainties that can be present in dispersion modeling. It is 

appropriate for the state to use such tools to increase the confidence in and other wise 

ensure that the predicted modeling results are accurate and borne-out in future air 

quality monitoring demonstrating attainment with the 8-hour standard. 

In addition, pursuant to EPA guidance, if modeling results indicate that the highest 

ozone levels will fall between 82 and 87 ppb, Colorado must conduct a "weight of the 

evidence" analysis and other supplemental analysis in order to corroborate the 

modeling results. Colorado's model results are within this range, and thus the state has 

conducted this analysis. The analysis supports the conclusion that Colorado will attain 

the standard by 2010, although by a narrow margin. To increase the certainty of the 

model results and the Weight of Evidence demonstration, the Commission concludes 

that these additional control measures are necessary to carry out its mandate to adopt a 

SIP that contains those elements that are necessary to assure attainment of the ozone 

NAAQS. 

Further, contrary to past ozone formation reductions in the DMAlNRFA, modeling has 

indicated that NOx reductions, in addition to VOC emissions reductions are beneficial in 

reducing ozone in the same area. The Division's meteorological analysis supports this 

conclusion. Thus, the Commission has adopted ozone reduction strategies that include 

both VOC and NOx emissions reductions. Modeling and supplemental analyses indicate 

that measures designed to reduce these precursors will be most effective in reducing 

ozone. 

The Division proposes to adopt additional controls for condensate tanks and pneumatic 

controllers located within the current ozone nonattainment area (the DMAlNFR). These 

revisions are based on reasonably available emission control techniques. All validated, 

reviewed and sound scientific methodologies made available by interested parties have 

been considered. Evidence in the record supports the finding that the rule shall result in 

a demonstrable reduction in ozone, and will reduce the risk to human health and the 

environment, and otherwise provides benefits justifying the costs. Among the options 

considered, the regulatory option chosen will maximize the air quality benefits in the 

most cost-effective manner. 

Condensate tanks are non-pressurized vessels installed at oil and gas facilities to store 

condensate, a petroleum product that is classified as a volatile organic compound 

(VOC), a ground level ozone precursor pollutant. Pneumatic controllers are natural gasactuated instruments used at oil and gas facilities. These instruments emit VOCs when 

the controller is actuated by pressurized natural gas and the associated volume of 

natural gas is bled to the atmosphere. VOCs are also emitted through the venting of 

associated valves, however these emissions are believed to be minimal. 

Proposed Regulations 3 and 7 SIP Revisions 

9/2/08 

4 
Reasonably Available Control Technology (RACT) requirements of Regulation 7 are 

proposed to be expanded such that they apply generally to any ozone non-attainment or 

attainment maintenance area, and not specific one-hour or eight-hour ozone nonattainment areas or early action compact areas. Additionally, there are two types of 

RACT required in Regulation 7 those developed by the state to address ozone and 

control technique guidelines (CTGs) which are developed by EPA. The CTGs must 

apply to all ozone non-attainment areas. The control technology requirements of 

Regulation 7 are proposed to be clarified in how they interact with Regulation 3, Part B, 

Section 11.0.2. 

The Division proposes to adopt the following revisions to Regulation 7 to ensure attainment 

with the current eight-hour ozone NAAQS set at 0.08 ppm, and to achieve additional ozone 

reductions in light of both the new eight-hour ozone NAAQS set at 0.075 ppm and the 

Governor's JUly 27, 2007 directive to proactively and pragmatically reduce ozone levels. 

II.	 Proposed Rule 

The Division's proposed revisions to Regulations 3 and 7 are part of an overall ozone 

reduction strategy to be incorporated into the Colorado SIP. The Division believes this 

strategy accomplishes five objectives: A) reduce vac emissions from oil and gas 

operations in the ozone non-attainment area, B) revise the control requirements for 

condensate tanks by transitioning from a system-wide to an emissions threshold control 

strategy in the ozone non-attainment area, C) expand vac RACT requirements such that 

all ozone non-attainment areas are subject to Regulation 7's RACT requirements, D) clarify 

how the RACT requirements in Regulations 3 and 7 interact in the ozone non-attainment 

area, E) improve the Division's inventory of specific source category emissions state-wide; 

and F) make typographical, grammatical and formatting changes for greater clarity and 

readability. 

A.	 Reduce voe Emissions from Oil and Gas Operations in the Ozone 

Non-attainment Area 

The proposal requires: 1) additional vac emissions reductions from condensate 

tanks in any ozone non-attainment area compared to the established control 

requirements identified in Regulation 7, Section XII., and 2) sets new vac 

control requirements for pneumatic controllers in any ozone non-attainment area 

in Regulation 7, Section XIII. 

.Condensate Storage Tanks 

The Division's proposal revises current condensate storage tank control 

requirements in Regulation 7, Section XII by reorganizing the rule, 

adding/revising definitions, setting additional control requirements for tanks, 

transitioning away from a system-wide control strategy to an emission threshold 

control strategy, adding monitoring requirements, and revises recordkeeping and 

Proposed Regulations 3 and 7 SIP Revisions 

9/2/08 

5 
reporting requirements. 

The Division proposes that tanks serving newly drilled, recompleted or 

stimulated wells be required to employ air pollution control equipment during 

the first 90 days of production. Air pollution control equipment can include 

combustion devices, vapor recovery units, or Division approved alternative 

controls or pollution prevention activities that meet the control efficiency 

requirement. If after the first 90 calendar days, the data shows that annual 

emissions from the tank will not exceed APEN reporting thresholds, the 

control may be removed. This requirement is designed to address the facts 

that production, and thus emissions, are greatest during the period 

immediately after drilling, recompletion or stimulation, and that the actual 

production/emission level is not known prior to drilling, recompletion or 

stimulation. Accordingly, significant vac emissions may occur before it can 

be determined whether a tank will need to install controls in accordance with 

the annual emission threshold requirement. By requiring controls on all tanks 

serving newly drilled, recompleted or stimulated wells, the proposed rule 

eliminates emissions during the initial period, while allowing owners and 

operators to remove controls after they can determine that emissions will not 

exceed the 2 ton per year threshold. 

The Division proposes enhanced monitoring provisions for condensate tanks 

as an indicator of compliance to ensure actual emissions reductions occur. 

The Division believes it is appropriate to require the installation and operation 

of auto-igniters and electronic surveillance for each combustion device. In 

many cases, condensate tanks are remotely located and un-manned. Autoigniters may be relied on to identify when the pilot is not lit and attempt to 

relight it, and ensure control operation. Electronic surveillance may be relied 

upon to document the duration of time when the pilot is not lit, and notify an 

operator that repairs are necessary to ensure proper control operation. 

In an effort to offset the added control operation assurance gained through 

enhanced monitoring, the Division proposed to minimize the requirements for 

emissions recordkeeping and reporting. This revision reduces the frequency 

and reporting of emissions estimation calculations, from a weekly to a 

monthly basis and from annual company-wide reporting to reporting upon 

request of the Division (normally during routine inspections or via APEN 

updates for significant increases in annual emissions). Emissions estimates 

are required to be maintained on a rolling-12 month basis. 

The Division's proposed rule will lower the applicability thresholds for existing 

tanks from 20 down to ten tons per year of actual uncontrolled vac 

emissions, beginning May 1, 2010. The control technology must reduce 

uncontrolled emissions by at least 95%. Affected tanks are required to 

Proposed Regulations 3 and 7 SIP Revisions 

9/2/08 

6 
control emissions by 95% and to monitor associated air pollution control 

equipment to ensure compliance. 

Finally, this revision reorganizes the requirements for condensate tanks for 

clarity. 

Pneumatic Controllers 

This revision establishes new VOC emission controls for pneumatic 

controllers in the 8-hour Ozone Non-attainment Area in Regulation 7, Section 

XVIII. Pneumatic controllers are widely used in the oil and gas industry, to 

control or monitor process parameters such as liquid level, gas level, 

pressure, valve position, liquid flow, gas flow and temperature. Pneumatic 

controllers are instruments that are actuated by natural gas pressure (some 

natural gas may be bled to the atmosphere from the pneumatic controller and 

some may be vented from the associated valve). vac emissions reductions 

from pneumatic controllers are specific to the bleeding of natural gas from the 

controller and not the venting from the valve, which is thought to be minimal. 

High-bleed controllers emit more than six standard cubic feet per hour (scth) 

of natural gas to the atmosphere, and low-bleed controllers emit less than or 

equal to six scfh of natural gas to the atmosphere. 

The oil and gas industry has already begun replacing high-bleed controllers 

with low-bleed controllers, understanding the financial gain of minimizing the 

bleed rate of pneumatic controllers and keeping the natural gas in the 

pipeline. 

Under this revision, most high-bleed controllers must be replaced with the 

equivalent of low -bleed or better pneumatic controllers by May 1, 2009. 

Pneumatic devices installed after February 1, 2009 must be replaced with the 

equivalent of low -bleed or better pneumatic controllers. There is an exception 

for high-bleed controllers that the source justifies to the Division as necessary 

for safety andlor process purposes. Operators must inspect and maintain 

high-bleed controllers on a monthly basis. Operators must also keep logs of 

the number of in-use high-bleed controllers, and the reason that each highbleed controller remains in place, and the inspection and maintenance of the 

in-use high-bleed controller. These revisions require operators to physically 

tag the in-use high-bleed controllers to enable the Division to track 

compliance. 

A 2003 EPA study reported that emissions from pneumatic controllers are 

collectively one of the largest sources of methane emissions in the natural gas 

industry. Estimated annual nationwide methane emissions are approximately 31 

billion cubic feet (Bct) from the production sector, 16 Bcf from the processing 

sector, and 14 Bcffrom the transmission sector. As stated above, by definition, 

high-bleed pneumatic controllers emit more than six scfh of natural gas to the 

atmosphere. The highest bleed rate listed in one source, a table published by the 

Proposed Regulations 3 and 7 SIP Revisions 

9/2/08 

7 
EPA, is 42 cubic feet per hour (cfh). The average bleed rate for high-bleed 

pneumatic controllers in the NAA is 21 cfh. Natural gas is primarily composed of 

methane, but also contains vac emissions which are ozone precursors. 

Therefore, emission reductions related to this source category have the potential 

to be significant. 

B.	 Transition from a System-wide to an Emissions Threshold Control 

Strategy in the Ozone Non-attainment Area 

As discussed above, the current rule governing condensate tanks does not 

require controls at any specific unit, but instead requires a system-wide reduction 

across all units. The theory behind this was to provide owners and operators 

with the flexibility to install controls where they saw fit. Because no particular 

unit had to be controlled, assessing compliance at any given point in time was 

close to impossible without an extremely extensive record-keeping system. In 

recognition of this, the current rule requires each company to maintain a 

spreadsheet listing all subject tanks, production data and control data on a daily 

basis in order to verify compliance with the daily system wide reduction 

requirement. Additionally, the regulation requires companies to submit an 

annual system-wide report describing in detail how they complied with the 

emission reduction requirements. Maintaining this spreadsheet, and calculating 

daily emission reductions has proved to be a very challenging and laborintensive proposition for industry (especially smaller companies). Reviewing this 

data has also proved onerous for the Division. Finally, based on the Division's 

review of the data from 2005, 2006 and 2007, it appears that for the most part, 

owners and operators have chosen to comply with the regulation by controlling 

their largest emitting units. Accordingly, the flexibility inherent in the current 

system-wide approach lacks the anticipated utility, while at the same time 

imposing burdensome requirements on both the regulated community and the 

Division. 

To alleviate the burdens inherent in the current regulatory scheme, the Division 

proposes moving from a system-wide reduction requirement to an emission 

threshold control requirement, whereby any tank that emits a certain amount of 

vacs will be required to install and operate an air pollution control device. By 

eliminating the system-wide reduction approach, the daily spreadsheet and 

annual compliance report are unnecessary to determine compliance with the 

rule. Instead, the proposed rule requires companies to track condensate 

production from each tank and identify periods where a required control device is 

not operating. These records will allow the Division to determine compliance at 

any given tank. The proposed rule does not require owners or operators to 

periodically submit these records to the Division, but does require that the 

records be maintained for a period of three years. The absence of a reporting 

requirement on an annual basis is consistent with the reporting requirement of 

other minor sources across the state. Moreover, the Division believes that given 

the Division's broad information gathering authority under the Colorado Air 

Pollution Prevention and Control Act, the lack of a reporting requirement will not 

Proposed Regulations 3 and 7 SIP Revisions 

9/2/08 

8 
impede the Division's ability to enforce the rule. 

In addition to seeking additional VOC emissions controls, the Division believes 

that the proposed transition from the system-wide to an emissions threshold 

control strategy is necessary in order for the Division to easily determine the 

compliance status of a source. In addition, the threshold control strategy 

increases control requirements in that more tanks are required to be controlled 

(i.e. all new or modified tanks greater than 2 tons per year). 

C. Expand and Clarify VOC RACT Requirements in the Ozone Nonattainment Area 

This proposal revises Regulation 7 to expand its application to all subject 

sources in any ozone non-attainment and attainment/maintenance areas. 

This regulation previously applied only to the One-hour Ozone NonAttainment Area. Accordingly, this regulation will apply to some sources that 

were previously outside of its geographic scope. These sources are not 

currently subject to adopted Control Technique Guidelines (CTGs) or general 

RACT requirements. This revision ensures equity across all designated 

ozone non-attainment areas, and complies with EPA's requirement that CTGs 

apply in all ozone non-attainment areas. 

Case-by-case RACT requirements of Sections I and II and general RACT 

requirements of Sections I and 111- XVIII do not apply consistently to all ozone 

non-attainment or attainment areas. Specific sections sometimes apply in the 

one-hour ozone non-attainment area, the eight-hour ozone control area, and 

sometimes state-wide. This revision expands Regulation 7's applicability to 

any ozone non-attainment or attainment/maintenance area. This is done 

intentionally to apply Regulation 7 requirements to current as well as any 

future ozone non-attainment or attainment maintenance areas in Colorado. It 

is possible, considering the current ozone NAAQS has been lowered from 

0.08 to 0.075 ppm and the difficulties experienced in some areas in attaining 

the ozone NAAQS, that Colorado will have additional areas designated as 

being in non-attainment with the new ozone NAAQS. 

This revision also clarifies how the Regulation 3 RACT requirements interact 

with Regulation Number 7. Currently, Regulation 3, Part B, Section 111.0. 

requires all new and modified minor sources of pollutants or precursors to 

pollutants for which the area has been designated as being in non-attainment 

or is currently in attainment/maintenance with a NAAQS to submit a RACT 

analysis and implement RACT. Further, Regulation 7 is currently unclear on 

whether existing sources that are modified (such that they have undergone a 

physical change or change in operation which causes an increase in 

emissions) become subject to new source requirements or not. This revision 

clarifies that existing sources that are modified are subject to the Regulation 

Proposed Regulations 3 and 7 SIP Revisions 

9/2/08 

9 
Number 3, Part B, Section II.D. requirements and are considered to be a new 

source for the purposes of Regulation 7. 

This revision also clarifies that the case-by-case RACT requirements of 

Regulation 7, Section II.C. only apply to existing, new and modified sources at 

which all air pollution generating activities at that source are already subject 

to RACT. 

D. Clarify RACT Requirements in Regulations 3 and 7 in the Ozone Nonattainment Area 

Regulation Number 3, Part B, Section III.D. currently requires RACT in ozone 

non-attainment areas for all new and modified sources emitting VOC or NOx 

emissions and commencing construction on or after February 1, 2009. This 

revision specifies that pursuant to Regulation 7, Section II.C., all existing 

sources that emit 100 tons per year of VOC emissions and that are located in 

the eight-hour ozone non-attainment area become subject to RACT. 

E. Improve Emissions Inventory State-Wide 

The Division's proposal removes and/or revises several categorical APEN 

reporting and/or permitting exemptions in Regulation Number 3, Parts A, Band 

C in order to improve the Division's emissions inventory and for the sake of 

equity. Proposed changes to exemptions fall in three categories: 1) specific 

APEN and permitting exemptions were removed altogether; 2) specific APEN 

exemptions were removed and permit exemptions were kept in place; and 3) 

specific APEN and permit exemptions were clarified, but kept in place. 

Remove APEN and Permitting Exemptions 

The current APEN and permit exemptions for condensate tanks were established 

using ~Iigher de minimis levels than currently apply. For example the condensate 

storage tank exemptions listed under Regulation Number 3, Part A, Section 

II.D.1.eeee. and Part C, Section Il.e.3.gggg., based on 730 barrels of production, 

was derived using a five ton per year VOC emissions de minimis level which 

applies to attainment areas, instead of the two ton per year de minimis level that 

applies to non-attainment areas. These current APEN and permit exemptions 

were established using higher de minimis levels than currently apply. This higher 

de minimis level for condensate tanks means that the Division has a limited 

inventory of emissions from condensate tanks that emit less than the five ton per 

year VOC de minimis level. 

Other source categories located in the 8-hour Ozone Non-attainment Area are 

required to submit an APEN if actual uncontrolled emissions of VOCs or NOx 

exceed one ton per year and obtain a permit if actual uncontrolled emissions of 

VOCs or NOx exceed two tons per year. Thus, there is an issue of equity, 

allowing one source category to be treated differently from others. Additionally, 

the condensate tank exemption is based on a standardized emission factor, 13.7 

pounds of VOC emissions per barrel of production, which may not be 

Proposed Regulations 3 and 7 SIP Revisions 

9/2/08 

10 
representative of each natural gas field. This APEN and permit exemption was 

removed. However, sources may still make use of the generic APEN exemption, 

by determining that actual annual uncontrolled emissions fall below the 

applicable de minimis levels identified in Regulation Number 3, Part A. If based 

on this generic exemption, a source is determined to be APEN exempt, the 

source is also permit exempt. 

Remove APEN Exemptions, Keep Permit Exemptions 

Based on the Division's experience, actual emissions from several source 

categories are anticipated to be higher than previously believed. These 

categories are: petroleum industry flares (Regulation 3, Part A, Section 

II.D.1.m.), crude oil truck loading (Regulation 3, Part A, Section II.D.1.ee.), oil 

production wastewater (Regulation 3, Part A, Section II.D.1.uu.) and crude oil 

storage tanks (Regulation 3, Part A, Section II.D.1.ddd.). The Division wants to 

better understand the actual annual uncontrolled emissions from these 

categories, however the Division has concerns that these source categories may 

trigger permitting requirements, and that the resulting permitting may require 

more Division resources than available. Thus, the Division's proposal is to 

remove the specific source category APEN exemptions - with the understanding 

that sources may still make use of the generic APEN exemption. 

Revise APEN and/or Permitting Exemptions 

Based on the Division's experience, actual emissions from several source 

categories specific to oil and gas related operations are higher than previously 

believed. Thus the APEN and permitting exemptions for surface water 

impoundments (Regulation 3, Part A, Section II.D.1.uuu. and Part C, Section 

II.E.3.yyy.) were revised to exclude from the exemption, oil and gas production 

wastewater (similar to Regulation 3, Part A, Section II.D.1.uu.). Also, the APEN 

and permitting exemptions for chemical storage tanks (Regulation 3, Part C, 

Section II.E.3.n.) were revised to exclude oil and gas production wastewater or 

commercial facilities' operations (similar to Regulation 3, Part A, Section 

II.D.1.uuu. and Part C, Section II.E.3.yyy.). 

Finally, the APEN and permitting exemptions for fuel storage dispensing 

(Regulation 3, Part A, Section II.D.1.cccc. and Part C, Section II.E.3.cccc.) were 

revised to expand the applicability of the current exemption from specifically the 

1-hour Ozone Non-attainment or Attainment/maintenance Area to any ozone 

non-attainment area to ensure VOC controls are required in all ozone nonattainment areas. 

F. Rule Reorganization and Other Changes 

The Division's proposal changes the title of Regulation 7 to include NOx.
 

An outline of sections is provided to better understand contents of Regulation
 

7. Outdated sections are removed (Le. Section II.F.1. specific to Gates 

Rubber Company, which is now out of business). Section XII, specific to 

Proposed Regulations 3 and 7 SIP Revisions 

9/2/08 

11 
condensate tanks in the ozone non-attainment area is reorganized for clarity. 

One appendix (new Appendix A) is added to provide maps of ozone nonattainment areas and chronologies of attainment designations, of which 

certain requirements key off. Finally, sections and appendices are 

renumbered and formatted as necessary. 

III.	 Conclusion 

The Division requests that the Commission modify the requirements set forth in Regulations 

3 and 7 to ensure future attainment with the current 8-Hour Ozone National Ambient Air 

Quality Standard (NAAQS) set at 0.08 ppm, and to achieve additional ozone reductions in 

light of both the new 8-Hour Ozone NAAQS set at 0.075 ppm and the Governor's July 27, 

2007 directive to proactively and pragmatically reduce ozone levels. 

ATTACHMENTS: 

1.	 Memorandum of Notice 

2.	 Regulation NO.7 - Proposed Language 

3.	 Regulation Number 7 Statement of Basis and Specific Statutory Authority and 

Purpose 

4.	 Regulation Number 3, Parts A, Band C - Proposed Language 

5.	 Regulation Number 3, Parts A, Band C - Statement of Basis and Specific 

Statutory Authority and Purpose 

6.	 Initial Economic Impact Analysis 

Proposed Regulations 3 and 7 SIP Revisions 

9/2/08 

12 
SIGNATURES: 

Preparer: Theresa Amoroso Date 

Supervisor: Dena M. Wojtach Date 

Program Manager: Kirsten Linnea King Date 

Division Director: Paul Tourangeau Date 

Proposed Regulations 3 and 7 SIP Revisions 

9/2/08 

13 
MEMORANDUM OF NOTICE 

Date: September 18,2008 

To: Colorado Air Quality Control Commission 

Subject: Proposed revisions to the Air Quality Control Commission's 

Regulation Number 3 & Regulation Number 7; Regulation 7 Sections 

I, II, VI, VII, VIII, XII, XVII, and XVIII 

GENERAL DESCRIPTION 

The Colorado Department of Public Health and Environment, Air Pollution Control 

Division ("Division"), in coordination with the Regional Air Quality Council (RAQC) 

and the Northern Front Range Metropolitan Planning Organization (NFRMPO) as the 

Lead Planning Agencies, requests that the Colorado Air Quality Control Commission 

("Commission") revise the requirements set forth in Regulation Number 7 and 

Regulation Number 3, to address ozone formation in the 8-hour ozone non-attainment 

area (a.k.a. the 9-county Denver Metro AreaINorth Front Range (DMA/MFR) NonAttainment Area (NAA) and state-wide. Specifically, the Division's proposed revisions 

serve to reduce volatile organic compound (VOC) emissions, an ozone precursor, and 

thus reduce ozone concentrations in ambient air. These revisions are necessary to ensure 

attainment with the current 8-Hour Ozone National Ambient Air Quality Standard 

(NAAQS) set at 0.08 parts per million (ppm), and to otherwise achieve ozone reductions 

in light of both the new 8-Hour Ozone NAAQS set at 0.075 ppm and the Governor's July 

27, 2007 directive to proactively and pragmatically reduce ozone levels. Also, the 

Division is proposing revisions to Regulation Number 3 to revise Air Pollution Emission 

Notice (APEN) reporting requirements to improve the Division's emissions inventory, to 

facilitate planning for development of additional emissions reductions strategies that may 

be needed to meet the Environmental Protection Agency's new ozone NAAQS, that 

lowers the standard from 0.08 ppm to 0.075 ppm. 

EXPLANATION OF PROPOSED RULES 

Specifically, the Division requests that the Commission set for public hearing the 

proposed revisions to Regulation 7 as follows: 

•	 change the title to identify NOx in addition to VOC as an ozone precursor, 

•	 modify the emission control requirements applicable to condensate storage tanks 

at oil and gas exploration and production operations, natural gas compressor 

stations and natural gas drip stations located in the 8-Hour Ozone Non-attainment 

Area (Regulation 7, Section (XII) to: 

•	 Reduce VOC emissions, 
Revise the control requirements for condensate tanks by 

transitioning from a system-wide to an emissions threshold control 

strategy in the ozone non-attainment area, 

Owners or operators of new or modified condensate storage tanks 

or tank batteries emitting 2 tpy VOC must control VOC emissions 

by 95% beginning May 1,2009, 

Owners or operators of existing condensate storage tanks or tank 

batteries emitting 10 tpy VOC must control VOC emissions by 

95% beginning May 1, 2010, and 

Condensate tanks serving wells that are drilled, stimulated or recompleted after February 1, 2009 must control VOC emissions by 

95% during the first 90 days from first production. After the 90­

day period, control equipment may be removed ifuncontrolled 

actual emissions from condensate tanks are less than 2 tpy VOC. 

•	 Monitoring: Owners or operators of condensate tanks required to control 

VOC emissions must inspect or monitor the control equipment to ensure it 

is operating each time condensate is loaded out from the tank. 

•	 Recordkeeping: Owners or operators required of condensate tanks shall 

maintain monthly condensate production records, actual controlled and 

uncontrolled emissions, and when air pollution control equipment is not 

operating. 

•	 set new emission control requirements for pneumatic controllers associated with 

oil and gas operations located in the 8-Hour Ozone Non-attainment Area 

(Regulation 7, Section XIII), 

All new controllers (after February 1,2009) must be at least low­


bleed,
 

All existing high-bleed controllers must be replaced with low­


bleed by May 1, 2009, and
 

A safety and or process exemption for in-use high-bleed devices is
 

available, however recordkeeping and reporting requirements
 

apply.
 

•	 expand the applicability of Reasonably Available Control Technology (RACT) 

requirements to existing, new and modified sources in ozone non-attainment areas 

outside of the historic I-hour Ozone Non-attainment or attainment/maintenance 

area (Regulation 7, Sections I-XVIII), 

•	 make typographical, grammatical and formatting changes for greater clarity and 

readability throughout Regulation 7, as necessary, and 

•	 make clarifications or corrections throughout Regulation 7, as identified: 

o	 outline regulation, 

o	 make corrections to definitions and corresponding numbering (II.AA.), 

o	 add ozone non-attainment area definition (II.A.I7.) , 

o	 delete regulations specific to Gates Rubber Plant because they no longer 

apply (Section II.F.), 

2 
o	 Clarify reporting requirement of every six months for operators of EFR 

tanks (Section VI.B.2.c.(2)(B)(i)), and 

o	 Clarify the applicability of Section VII.A.2 to include sections XII and 

XVII. 

Additionally, the Division requests that the Commission adopt proposed revisions to 

Regulation 3 to revise APEN reporting exemptions for specific source categories. This 

will improve the Division's inventory of specific source category emissions state-wide 

(Regulation 3, Part A, Section II.D., Part B, Section II.D., and Part C, Section II.E.). 

MATERIALS TO BE INCORPORATED BY REFERENCE 

No materials will be incorporated by reference in the proposed rule revisions. 

BACKGROUND ON DEVELOPMENT OF THE PROPOSED RULE 

Problem Statement 

Even at low levels, ground-level ozone can cause acute respiratory problems, aggravate 

asthma, cause significant temporary decreases in lung capacity of even of healthy adults, 

cause inflammation of lung tissue and reduce the lung's capacity to fight disease. There 

appears to be no "safe" inhalation level of ozone for humans. It is even more toxic to 

plants, e.g. crops and natural flora, as well as destructive to rubber and other materials in 

the built environment. Ozone is formed when VOCs react with NOx and other pollutants 

in the presence of sunlight, especially on long, hot, sunny days. Therefore, the ozone 

season is designated to be May through September. 

Numerous exceedances of the national 8-Hour Ozone Standard during 2003 brought the 

Colorado Ozone Control Area into violation status for the 3-year period from 2001-2003. 

In response, the Colorado Early Action Compact (EAC) was formed, which produced a 

federally enforceable Ozone Action Plan (approved by the Commission March 12,2004). 

The plan was designed to address VOC emissions quickly and avoid an EPA 

nonattainment designation for the 8-hour ozone standard. 

The Commission initially adopted Section XII of Regulation Number 7 in Mach of2004 

in connection with the EAC to defer an ozone non-attainment designation for the 8-Hour 

Ozone Control Area. However, VOC emissions in 2004 already far surpassed the 2007 

"cap." Therefore, the regulation was amended in December 2006. 

As a result, Section XII currently requires that owners and operators of condensate tanks 

in the 8-Hour Ozone Control Area achieve a 75% reduction in overall VOC emissions 

through 2011; beginning in 2012, 78%, as well as a 70% reduction during the non-ozone 

season. Because the regulation requires system-wide reductions and does not mandate 

reductions from specific units, it entails extensive recordkeeping and reporting to ensure 

compliance. Companies must maintain daily spreadsheets reflecting the total system-wide 

3 
daily percentage reduction, identify each tank subject to the regulation, list daily
 

condensate production for each tank, list the emission factor for each tank, identify the
 

location and control efficiency for each condensate tank air pollution control device, and
 

note any periods when control devices are not operating.
 

Despite additional reductions obtained via regulatory amendment, the national 8-Hour
 

Ozone National Ambient Air Quality Standard was exceeded in Summer 2007. The 8­


Hour Ozone Control Area was designated as an EPA nonattainment area on November
 

20,2007. As a result, Regulation Number 7 is being proposed to be amended, as
 

described in this document.
 

How do proposed regulatory revisions help solve the problems?
 

The proposed revisions would lead to VOC emission reductions beneficial in achieving
 

ozone formation in the non-attainment area to achieve attainment with the ozone
 

standard, thus bringing the area out of nonattainment.
 

How were proposed regulatory revisions developed?
 

Ambient air monitoring data showed that ozone levels in the 8-Hour Ozone Control Area
 

exceeded NAAQS by late Summer 2007. Therefore, the EAC deferral expired and the 8­


Hour Ozone Control Area was designated as a non-attainment area on November 20,
 

2007. The RAQC, NFRMPO and the Division began holding publicly announced
 

stakeholder meetings in Fall 2007. Stakeholders attending meetings have included
 

representatives from industry, consultants, EAC member agencies, government agencies,
 

EPA, environmental groups, and the general public. Five stakeholder meetings were held
 

which addressed proposed rule language for Stationary Sources. Input from all sectors
 

has helped to craft the proposed regulatory revisions included in this packet.
 

How do proposed regulatory revisions affect the public, regulated community, and other
 

agencies?
 

The proposed revisions will protect pubic health by reducing VOC emissions, an ozone
 

precursor, which will reduce the potential for ozone formation and improve air quality.
 

The regulated community will be required to: 1) place control and monitoring equipment
 

on additional condensate tanks, 2) reduce emissions from pneumatic controllers by
 

replacing most high-bleed controllers with low-bleed controllers (or by other means that
 

will reduce emissions, such as using solar powered devices), 3) report emissions at lower
 

thresholds, 4) implement RACT in the ozone NAA. An analysis of the costs associated
 

with the additional controls is set forth in the Initial Economic Impact Analysis included
 

with this package.
 

Other government agencies will benefit from the proposed rule revisions via improved air
 

quality.
 

How do the proposed rule revisions relate to federal and adjacent state requirements?
 

The Division contacted adjacent states to better understand their approaches towards
 

condensate storage tanks and pneumatics. The proposed revisions will decrease ozone
 

4 
precursor formation which is beneficial to states downwind. It is noted that Wyoming 

and Utah use BACT in their minor source permitting programs. 

Arizona: Arizona's permit de minimis is 40 tpy potential to emit (PTE). There is no 

BACT for minor sources, although they are considering implementing it in future. 

Condensate Tank Batteries and Pneumatic Controllers: The oil and gas industry is 

limited to pipelines and fuels, therefore condensate tanks and pneumatic controllers are 

not specifically regulated at this time. 

Kansas: Kansas' permit de minimis is 40 tpy PTE. 

Condensate Tank Batteries: Some specific permits require controls however as a source 

category, tank batteries are not specifically regulated at this time. 

Pneumatic Controllers: Pneumatic controllers are not specifically regulated at this time. 

Nebraska: Nebraska issues construction permits at 40 TPY for VOC emissions. 

Condensate Tank Batteries and Pneumatic Controllers: The oil and gas industry is not 

specifically regulated at this time for VOCs (more concerned about NOx). 

New Mexico: New Mexico's permit de minimis is 25 tpy PTE. There is no BACT for 

minor sources, although they are considering implementing it in future. 

Condensate Tank Batteries and Pneumatic Controllers: Condensate tanks and pneumatic 

controllers are not specifically regulated at this time, although they are planning to 

implement changes that resemble Colorado's Regulation 7. 

Utah: Utah's permit de minimis is 5 tpy actual emissions. A BACT analysis is required 

for all sources above de minimis levels. 

Condensate Tank Batteries and Pneumatic Controllers: The oil and gas industry is not 

specifically regulated at this time; all rules are at the Federal level. They are currently 

building an inventory and may regulate in future. 

5 
Wyoming: BACT is required as discussed below.
 

Condensate Tank Batteries: Minor source BACT program requires controls on all
 

condensate tank batteries within 60 days of production statewide if predicted emissions
 

are 20 tpy or greater. Controls may be removed after 1 year if emissions decline to less
 

than 15 tpy. Minor source BACT program requires controls on all tank batteries upon
 

first day of production in the Jonah/Pinedale Area Development (JPAD). Controls
 

remain for the life of the tank battery.
 

Pneumatic Controllers: Considering regulating pneumatic controllers by requiring one of
 

three options: using low/no bleed devices, tie vent gas into gas line, or using compressed
 

air rather than natural gas as actuating gas. Currently, BACT must be considered for
 

statewide pneumatic pumps exceeding thresholds. In addition, all new and modified
 

pneumatic pumps in the JPAD must be controlled.
 

How will the regulatory revisions be implemented?
 

The rule will be implemented through Regulations 3 and 7. The amended rules will be
 

placed on the Commission website. Division personnel will be informed of these
 

changes to ensure that the amended rules will be implemented.
 

Are there time constraints?
 

If adopted, the proposed amendments to Regulations 3 and 7 will become effective in
 

February 2009 such that VOC emissions reductions will occur for the next ozone season
 

(beginning May 1,2009). However, industry and the Division will need some time in
 

order to implement these rules. Finally, adoption of the revisions must occur before
 

December 31, 2008 in order to meet SIP submittal deadlines.
 

What if the Air Quality Control Commission does not adopt the proposed Rule revisions?
 

If the Commission does not adopt any changes to Regulations 3 and 7 by December 31,
 

2008, Colorado may not achieve attainment by 2010, will miss the SIP submittal
 

deadline, and may become subject to EPA's imposing ofa Federal Implementation Plan.
 

Photochemical grid dispersion modeling indicates that without further emission controls,
 

Colorado will attain the 8-hour standard by 2010. The dispersion modeling reflects that
 

Colorado would attain the standard by a narrow margin - within 0.001 ppm on a standard
 

of 0.084 ppm. Photochemical dispersion modeling analysis is the primary tool used to
 

assess present and future air quality trends, and is required for EPA to approve the state
 

attainment demonstration in the SIP. Dispersion modeling results have an inherent level
 

of uncertainty, as recognized in EPA guidance, and it is appropriate for a state to use
 

other tools at its disposal, including further control measures, to address and mitigate any
 

uncertainties that can be present in dispersion modeling. It is appropriate for the state to
 

use such tools to increase the confidence in and other wise ensure that the predicted
 

modeling results are accurate and borne-out in future air quality monitoring
 

demonstrating attainment with the 8-hour standard.
 

6 
In addition, pursuant to EPA guidance, if modeling results indicate that the highest ozone 

levels will fall between 0.082 and 0.087 ppm, Colorado must conduct a "weight ofthe 

evidence" analysis and other supplemental analysis in order to corroborate the modeling 

results. Colorado's model results are within this range, and thus the state has conducted 

this analysis. The analysis supports the conclusion that Colorado will attain the standard 

by 2010, although by a narrow margin. To increase the certainty of the model results and 

the Weight of Evidence demonstration, the Commission concludes that these additional 

control measures are necessary to carry out its mandate to adopt a SIP that contains those 

elements that are necessary to assure attainment ofthe ozone NAAQS. 

Further, contrary to past ozone formation reductions in the DMAlNRF, modeling has 

indicated that NOx reductions, in addition to VOC emissions reductions are beneficial in 

reducing ozone in the same area. The APCD's meteorological analysis supports this 

conclusion. Thus, the Commission has adopted ozone reduction strategies that include 

both VOC and NOx emissions reductions. Modeling and supplemental analyses indicate 

that measures designed to reduce these precursors will be most effective in reducing 

ozone. 

JUSTIFICATION FOR DIFFERING FROM FEDERAL REQUIREMENTS 

The federal act does not expressly require the controls being proposed by the Division. 

Rather, federal law establishes the 8-hour ozone NAAQS and requires the State to 

develop a SIP adequate to attain the NAAQS. The Division proposes to adopt revisions 

to Regulations 3 and 7 to ensure attainment with the current 8-hour ozone NAAQS set at 

0.08 ppm, and to achieve additional ozone reductions in light of both the new 8-hour 

ozone NAAQS set at 0.075 ppm and the Governor's July 27, 2007 directive to 

proactively and pragmatically reduce ozone levels. 

RANGE OF REGULATORY ALTERNATIVES
 

The Commission could choose to adopt the Division proposal into the SIP, adopt as state­


only regulations, or not adopt the proposal at all. Pursuant to C.R.S. §25-7-105(1)(a)(I),
 

the Commission must adopt such measures as are necessary to ensure compliance with
 

the NAAQS. The Division believes these proposed revisions carry out this mandate.
 

NO-ACTION ANALYSIS
 

If the Commission does not adopt any changes to Regulations 3 and 7 by December 31,
 

2008, Colorado may not achieve attainment by 2010, will miss the SIP submittal
 

deadline, and may become subject to EPA's imposing of a Federal Implementation Plan.
 

PUBLIC MEETINGS
 

The RAQC, NFRMPO, and the Division have held multiple meetings beginning in the
 

Fall 2007 to develop ozone reduction strategies. The RAQC and the Division have held
 

meetings specific to rule language development. If the Commission grants the request for
 

hearing ofthis proposal, the Commission will hold a Rulemaking Hearing on the
 

proposed rule. The Commission will establish a pre-hearing process to ensure an orderly
 

hearing. Anyone may participate in the pre-hearing and hearing process by obtaining
 

7 
party status in accordance with the Commission's Procedural Rules. Additional meetings 

may be held outside the pre-hearing process if there is sufficient interest from 

stakeholders. 

CONTACT INFORMATION: 

For more information please contact: 

Theresa Amoroso 

Regulatory Development 

Stationary Sources Program 

Air Pollution Control Division 

4300 Cherry Creek Drive South 

Denver, CO 80246-1530 

Phone: (303) 692-3111 

Fax: (303) 782-0278 

E-mail: theresa.amoroso@state.co.us 

8 
Initial
 

Economic Impact Analysis
 

for
 

Proposed State Implementation Plan Revisions to the Air Quality Control Commission's
 

Regulation Number 3 and Regulation Number 7
 

Regulation 3, Parts A, B, and C
 

Regulation 7, Sections I-XVIII
 

Per C.R.S. 25-7-110.5
 

September 18, 2008
 

I. REQUIREMENTS FOR ECONOMIC IMPACT ANALYSIS (EIA) 

Section 25-7-110.5 (4)(a), c.R.S. sets forth the requirements for initial and final Economic 

Impact Analysis, as stated below: 

"Before any permanent rule is proposed pursuant to this section, an initial economic 

impact analysis shall be conducted in compliance with this subsection (4) of the proposed 

rule or alternative proposed rules. Such economic impact analysis shall be in writing, 

developed by the proponent, or the Division in cooperation with the proponent and made 

available to the public at the time any request for hearing on a proposed rule is heard by the 

commission. A final economic impact analysis shall be in writing and delivered to the 

technical secretary and to all parties of record five working days prior to the prehearing 

conference. If no prehearing conference is scheduled, the economic impact analysis shall 

be submitted at least ten working days before the date of the rule-making hearing. The 

proponent of an alternative proposal will provide, in conjunction with the Division, a final 

economic impact analysis five working days prior to the prehearing conference. The 

economic impact analyses shall be based upon reasonably available data. Except where 

data is not reasonably available, or as otherwise provided in this section, the failure to 

provide an economic impact analysis of any noticed proposed rule or any alternative 

proposed rule will preclude such proposed rule or alternative proposed rule from being 

considered by the Commission. Nothing in this section shall be construed to restrict the 

Commission's authority to consider alternative proposals and alternative economic impact 

analyses that have not been submitted prior to the prehearing conference for good cause 

and so long as parties have adequate time to review them." 

The Air Pollution Control Division (Division) has selected C.R.S. § 25-7-110.5(4)(c)(III), which 

calls for an EIA that: 

(A) Identifies the industrial and business sectors that will be impacted by the proposal; 

and 

(B) Quantifies the direct cost to the primary affected business or industrial sector; and 

(C) Incorporates an estimate	 of the economic impact of the proposal on the supporting 

business and industrial sectors associated with the primary affected business or 

industry sectors. 

An EIA need only be based upon reasonably available data (§25-7-110.5(4)(a), C.R.S.). 

1 
II. DISCUSSION 

Analysis Background 

This Economic Impact Analysis (EIA) considers impacts from implementing proposed 

regulations that are aimed at reducing ground level ozone within the nonattainment area (NAA) 

by reducing emissions of ozone precursors, volatile organic compound (VOC) from the 

following sources: 

•	 Oil and gas industry condensate tanks in the ozone non-attainment area, 

•	 Oil and gas industry pneumatic controllers in the ozone non-attainment area, 

•	 Multiple industries through expansion of Regulation 7 Reasonably Available Control 

Technology (RACT) applicability in the ozone non-attainment area, and 

•	 Multiple industries through revising Regulation 3 Air Pollution Emission Notice (APEN) 

reporting and permitting exemptions state-wide (this strategy alone will not reduce VOC 

emissions; it is intended to provide information and increase equity). 

These proposed revisions are necessary to ensure attainment with the current 8-Hour Ozone 

National Ambient Air Quality Standard (NAAQS) set at 0.08 parts per million (ppm), and to 

otherwise achieve ozone reductions in light of both the new 8-Hour Ozone NAAQS set at 0.075 

ppm and the Governor's July 27, 2007 directive to proactively and pragmatically reduce ozone 

levels. 

Proposed Rules 

These proposed revisions accomplish five objectives: A) reduce volatile organic compound 

(VOC) emissions from oil and gas operations in the ozone non-attainment area, B) revise the 

control requirements for condensate tanks by transitioning from a system-wide to an emissions 

threshold control strategy in the ozone non-attainment area, C) expand VOC RACT requirements 

such that all ozone non-attainment areas are subject to Regulation 7' s RACT requirements, D) 

clarify how the RACT requirements in Regulations 3 and 7 interact in the ozone non-attainment 

area, E) improve the Division's inventory of specific source category emissions state-wide; and 

F) make typographical, grammatical and formatting changes for greater clarity and readability. 

Condensate Tank Proposed Rules in the Ozone Non-attainment Area 

Proposed rules further reduce VOC emissions by: 1) requiring control device and monitoring 

equipment installation and operation during the first 90 days of operation beginning February 1, 

2009; 2) redefining modification activities that trigger additional control and monitoring 

equipment installation and operation beginning February 1, 2009; 3) lowering the applicability 

thresholds for new and modified tanks from five down to two tons per year ofVOCs beginning 

February 1,2009 and for existing tanks from 20 down to 10 tons per year ofVOCs; and 4) 

increasing control requirement by initially increasing system-wide control requirements in May 

1, 2009, ultimately transitioning to a emissions threshold control strategy beginning in May 1, 

2010. Affected tanks are required to control emissions by 95% and to monitor associated air 

pollution control equipment to ensure compliance. 

2 
Tanks serving newly drilled, recompleted or stimulated wells be required to employ air pollution 

control equipment during the first 90 days of production. Air pollution control equipment can 

include combustion devices, vapor recovery units, or Division approved alternative controls or 

pollution prevention activities that meet the control efficiency requirement. If after the first 90 

calendar days, the data shows that annual emissions from the tank will not exceed the control 

requirement threshold, the control may be removed. 

Enhanced monitoring provisions are proposed for condensate tanks as an indicator of compliance 

to ensure actual emissions reductions occur. In many cases, condensate tanks are remotely 

located and un-manned. For combustion control devices (flares), auto-igniters and electronic 

surveillance systems are required to identify when the pilot is not lit and attempt to relight it, 

document the duration of time when the pilot is not lit, and notify an operator that repairs are 

necessary to ensure proper control operation and ensure control operation. 

Proposed recordkeeping and reporting requirements are minimized to offset the added control 

assurance gained through enhanced monitoring. This revision reduces the frequency and 

reporting of emissions estimation calculations, from a weekly to a rolling-12 month basis and 

from annual company-wide reporting to reporting upon request of the Division (normally during 

routine inspections or via APEN updates for significant increases in annual emissions). 

Pneumatic Controller Proposed Rules in the Ozone Non-attainment Area 

Proposed rules require new pneumatic controllers be at least low-bleed devices beginning 

February 1, 2009, and existing high-bleed pneumatic devices be retrofit or replaced with lowbleed devices, or devices with equivalent or lower VOC emissions, by May 1,2009. An 

exception will allow high-bleed devices to be used if the Division determines that a safety or 

process reason makes it technically infeasible to use a low-bleed device. Operators will be 

required to inspect high-bleed devices on a monthly basis and perform maintenance as needed. 

Operators will be required to keep logs of the number of devices, device type, and inspection and 

maintenance that is performed. Operators will be required to tag the devices, which will help 

enable the Division to track compliance. 

Regulation 7 Expansion ofRACT Proposed Rules in the Ozone Non-attainment Area 

Proposed rules will require that Regulation 7 expand the applicability of Reasonably Available 

Control Technology (RACT) requirements to existing, new, and modified sources outside of the 

historic I-hour Ozone Non-attainment or Attainment/Maintenance Area, beginning February 1, 

2009. 

This proposed regulation change is based on equity - sources in the I-hour Ozone Nonattainment or AttainmentlMaintenance Area already comply with Regulation 7. The Division 

believes all ozone non-attainment areas (existing and future designations) should comply with 

Regulation 7. 

Regulation 3 Exemptions Proposed Rules State-wide 

Proposed rules will revise APEN reporting exemptions for specific source categories, beginning 

February 1,2009. This regulation change is based on equity. Most sources ofVOC emitting 

one or more ton per year file an APEN and obtain a permit if they emit two or more tons per year 

in the ozone non-attainment area (or two or more ton per year file an APEN and obtain a permit 

3 
if they emit five or more tons per year in all other areas). This proposal requires source 

categories currently exempt from these thresholds to obtain APENs and permits at those same 

thresholds as other sources in the respective areas. 

Edits to Regulation 7 Proposed Rules 

Proposed rules will be revised to correct typographical, grammatical and formatting changes, as 

necessary, beginning February 1, 2009. 

Data Used in EIA 

To perform the EIA, the following information must be obtained to calculate industry's costs to 

implement the proposed regulation: 1) number of control and monitoring devices required, 2) 

associated costs, and 3) emission reductions that can be achieved. 

For those proposals specific to Regulation 7 expansion of RACT, Regulation 3 Exemptions and 

edits to Regulation 7, detailed data is not reasonably available. There are innumerable types of 

facilities that would be subject to these Regulation 3 and 7 proposed rules. For example, any 

emission source in an ozone non-attainment area that emits VOC emissions would be subject to 

the expansion of RACT, and since not previously subject to RACT, these sources may have 

never been required to report emissions to the Division. Such facilities include, without 

limitation, oil and gas facilities, food processing and packaging facilities, refineries, dry cleaners, 

printers and other surface coating operations. Within each of these categories, there are many 

different facilities of varying sizes and configurations, which compounds the difficulty in 

estimating costs of VOC emissions control. While potential costs associated with undertaking an 

analysis of control technology may be capable of general estimation and quantification, the 

potential costs associated with installing control technologies do not lend themselves to the same 

analysis. Such information is not reasonably available, in that it is so fact-specific as to preclude 

meaningful, generalized analysis. Such costs would be dependent upon numerous site-specific 

factors, including the type of facility, the amounts and types and constituents emitted by the 

facility, the concentrations of odors, the configuration of the facility (for example, whether there 

is space available to install certain types of equipment). Thus, the Division has an inaccurate 

inventory of these sources and associated emissions at this time and limits any cost analysis 

which may be performed. This is also true for sources affected by Regulation 3 reporting and 

permitting exemption changes. Clarifying edits to Regulation 7, edits are minimal and impacts 

are believed to be negligible 

Thus the Division focused efforts on this economic impact analysis on impacts to the oil and gas 

industry in controlling emissions from condensate tanks and pneumatic controllers. 

Condensate Tank EIA Data 

The number of units (tanks or tank batteries) that will need to install control devices and conduct 

monitoring under the proposed rule and the controlled and uncontrolled emissions from large 

units were based on the Division's emissions inventory (data reported to the Division by industry 

via APENs) for the 2007 inventory year. 

The number of small tanks or tank batteries (those having actual uncontrolled emissions of equal 

to or more than 10 tpy uncontrolled VOC emissions) that will need to install control devices 

4 
under the proposed rule was based on the Division's emissions inventory for the 2007 inventory 

year. Because the current reporting threshold is higher than five tons per year, and therefore the 

Division's emissions inventory is limited, the controlled and uncontrolled emissions from small 

units were based on data gathered within the ozone non-attainment area by Independent 

Petroleum Association of Mountain States (lPAMS). 

The cost of controlling emissions was based on data collected from the oil and gas industry. 

Pneumatic Controller EIA Data 

The number of high-bleed pneumatic controllers in place and associated emission reductions that 

could be obtained by retrofitting or replacing some of them were estimated based on data 

gathered within the ozone non-attainment area by IPAMS. The percentage of high-bleed 

pneumatic controllers that will be replaced or retrofit is based on data gathered by the Division 

from industry. 

Controller capital, installation, and maintenance cost data was obtained from vendors. Because 

this strategy increases the amount of natural gas that companies can sell, the strategy pays for 

itself. The U.S. natural gas wellhead price used in this analysis, $10.82 per thousand standard 

cubic foot, was current as of June 2008. 

Regulation 7 Expansion of RACT EIA Data 

Cost data is not readily available for this proposed regulation change. Industry has not indicated 

that this proposed regulation change will have a significant impact. 

Regulation 3 Exemptions EIA Data 

Cost data is not readily available for this proposed regulation change. The cost of filing an 

APEN is $152.90. Annual fees and permit fees vary by source type. 

Edits to Regulation 7 EIA Data 

Cost data is not available to this proposed regulation change. Industry has not indicated that this 

proposed regulation change will have a significant impact. 

Impact to Public 

The public will be indirectly affected by the proposed rule. Reductions in VOC emissions will 

reduce the incidence of ozone induced human health impacts caused by pulmonary, 

cardiovascular, respiratory, and nervous system disease. Ozone damages crops, forests, and 

other natural plant life, so these will benefit ifVOC emissions are reduced. Reducing emissions 

from pneumatic controllers will also reduce methane, which is a greenhouse gas and contributes 

to climate change. It is not within the scope of this analysis to determine if the public will face 

increased costs associated with the proposed regulation. 

The associated benefit of improved public and environmental health from this proposal is 

difficult to assess. 

Impact to Administration 

5 
Implementing the proposed rule has the potential to significantly increase the number of 

regulated sources, and has reporting, permitting, and/or compliance assurance impacts to the 

Division. It is beyond the scope of this analysis to determine costs to the Division associated 

with rule implementation. 

III. ECONOMIC IMPACT ANALYSIS 

Various industrial and business sectors will be impacted by this proposal: 

•	 Oil and gas (controls for condensate tanks, reducing use of high-bleed pneumatic
 

controllers), and
 

•	 Other stationary sources ofVOC. 

Supporting business and industrial sectors associated with the primary affected business and
 

industry sectors will benefit by selling equipment to the primary affected business and industrial
 

sectors. For example, as a result of the proposed regulation, more flares will be sold and, in the
 

short term, more low-bleed pneumatic controllers will be sold to replace the high-bleed
 

controllers currently in the field. Calculating supporting economic impacts is beyond the scope
 

of this document.
 

As directed by CRS 25-7-110.5, this EIA does not include an analysis of any nonmarket costs or
 

external costs asserted to occur notwithstanding compliance by a source with applicable
 

environmental regulations.
 

Direct costs to the primary affected business and industrial sectors are shown in the remainder of
 

this section.
 

Condensate Tank EIA for 8-hour Ozone Non-Attainment Area (NAA)
 

Table 1: 8-hour Ozone NAA Retrofit of Condensate Tanks with Flare Control Device and
 

Surveillance System
 

Tanks Cost Analysis: 

Flares @ 95% CE 

>10 and <20 tpy 

uncontrolled 

Controlled VOC Emissions 

(tpd) 

(tpy) 

27.2 

9,936 

Annualized Cost Per Unit $8,419 

Number of Units Controlled 773 

Cost Per Ton $655 

6 
Table 2: Condensate Tank Annualized Costs for Flare Control Device and Surveillance System 

Condensate Tank: Flare Control Device wiSurveillance Svstem 

Item 

Capital 

Costs 

(one time) 

Non Recurring 

(one time) 

O&M 

(recurring) 

Annualized Total 

Cost 

(15yrs) 

Flare $16,540 - -

$8,419 

Freight & Design - $1,500 -

Flare Installation - $6,354 -

Auto Igniter $1,500 - -

Surveillance System $3,600 - - Pilot Fuel - - $1,897 

Maintenance - - $2,000 

Data Management - - $1,000 

Subtotal Costs $21,640 $7,854 $4,897 

Annualized Costs $2,999 $524 $4,897 

Table 3: 8-hour Ozone NAA Retrofit of Condensate Tanks with Vapor Recovery Unit (VRU) 

Control Device 

Tanks Cost Analysis: 

VRU (ii) 95% Control 

>10 and <20 tpy 

uncontrolled 

Controlled VOC Emissions 

(tpd) 

(tpy) 

27.2 

9,936 

Annualized Cost Per Unit $19,078 

Number of Units Controlled 773 

Cost Per Ton $1,484 

Table 4: Condensate Tank Annualized Costs for Vapor Recovery Unit Control Device 

Co~densate Tank: Vapor Recovery Unit (VRU Cost Analysis 

Item 

Capital 

Costs 

(one time) 

Non 

Recurring 

(one time) 

O&M 

(recurring) 

Fuel Sales 

(recurring) 

Annualized 

Total Cost 

(15yrs) 

VRU $78,000 - - -

$19,078 

Freight & Design - $1,500 - - VRU Installation - $10,154 - -

Maintenance - - $8,553 - Recovered Natural 

Gas - - - ($1,063) 

Subtotal Costs $78,000 $11,654 $8,553 ($1,063) 

Annualized Costs $10,810 $777 $8,553 ($1,063) 

7 
Pneumatic Controller EIA for 8-hour Ozone NAA 

Pneumatic Controller: Converting to Low-Bleed Controllers and Peiforming 

Enhanced Maintenance on Remaining High-Bleed Cost Analysis 

Number of High-Bleed Controllers 5,524 

Number of Converted Controllers' 5,248 

Number of Remaining High-Bleed Controllers 276 

Controlled Emissions (tons per day/year) 23.3 /8,496 

Annualized Cost per Controller ($1,505) 

Cost per Ton ($747) 

1 Number of high-bleed controllers that can be retrofit or replaced with low-bleed controllers is calculated by 

assuming a 95% conversion rate 

8 
State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)
 

Interstate Transport Regarding 8-Hour Ozone
 

DRAFT
 

November 5, 2008 

Colorado Department of Public Health and Environment 

Air Pollution Control Division 

4300 Cherry Creek Drive South 

Denver, Colorado 80246 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

i
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table of Contents
 

1. OZONE-SPECIFIC PROVISIONS TO MEET THE REQUIREMENTS OF CAA llO(A)(2)(D)(I)­

INTERSTATE TRANSPORT 1 

1.1. INTRODUCTION I 

1.2. COLORADO OZONE MONITORING NETWORK 2 

1.3. OZONE MONITORING NETWORK IN NEARBY STATES 7 

104. OZONE TRANSPORT CONCLUSIONS FROM THE DMAINFR PHOTOCHEMICAL MODELING 10 

1.4.1. Emission Inventories and 2006 and 2010 Base Case II 

1.4.2. Discussion of2010 Base Case CAMx Modeling Resufts 15 

1.5. DENVER METRO AREAINORTH FRONT RANGE OZONE NONATTAINMENT AREA CONTRIBUT10N TO 

DOWNWIND LOCATIONS 18 

1.6. SECTION II 0(A)2 - OZONE TRANSPORT CONCLUSIONS 20 

2. REFERENCES 22 

List of Tables 

Table 1: 2008 I-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008) 4 

Table 2: 2008 8-Hour Ozone Monitored Concentration (updated through Sept. 30,2008) 5 

Table 3: Monitored 8-Hour Design Value Using the 3-Year (2006-2008) Average of the Fourth 

Maximum Ozone Concentration 6 

Table 4: 2005-2007 3-Year Fourth Highest Average Monitoring Concentrations from Kansas, 

Nebraska, New Mexico, Utah and Wyoming (see Table 5 for additional data) 7 

Table 5. 2005-2007 3-Year Fourth Highest Average Monitoring Concentrations from Kansas, 

Nebraska, New Mexico, Utah and Wyoming (see Table 4 for additional data) 8 

Table 6. Base Case Inventories for 8-Hour Ozone DMA/NFR NAA Photochemical Modeling 14 

List of Figures 

Figure 1. Location of Front Range Ozone Monitors 2 

Figure 2. Location of Statewide Ozone Monitors 3 

Figure 3: 8-Hour Ozone Nonattainment Areas 9 

Figure 4. Nested 12/4 km modeling domains for the Denver CAMx air quality and SMOKE 

emissions modeling 10 

Figure 5. Projected 2010 8-hour ozone Design Values (DVF) 15 

Figure 6. Rocky Flats North source apportionment for 29 July including boundary conditions 16 

Figure 7: Spatial extent of the 8-hour ozone concentrations that occurred between lOam and 6pm 

local time on June 27, 2002 through July 1, 2002 19 

ii 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of 

. Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

iii
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) -Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1. Ozone-Specific Provisions to Meet the Requirements of 

CAA 11 O(a)(2)(D)(i) - Interstate Transport 

1.1. Introduction 

The purpose of this document is to provide a technical basi s for the State of Colorado's 

plan to meet the requirements of the Clean Air Act Section 110 (a)(2)(D)(i) Interstate 

Transport requirements regarding the 0.08 parts per million (ppm) 8-Hour Ozone National 

Ambient Air Quality Standard (NAAQS). This addresses the applicable components of 

11 0(a)(2)(D)(i) demonstrating adequate provisions to prevent emissions from Colorado 

from interfering with attainment or maintenance of the federal ozone NAAQS in any other 

state. This analysis does not address ozone transport for the revised 0.075 ppm 8-Hour 

Ozone NAAQS. 

This document replaces the section titled "Ozone-Specific Provisions" in the document 

"State of Colorado Implementation Plan to Meet the Requirements of Clean Air Act 

Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone and PM25 

NAAQS." 

Currently, the Denver area is the only area in U.S. Environmental Protection Agency 

(EPA) Region VIII that is designated as nonattainment for the 8-hour ozone NAAQS of 

0.08 ppm. 

In this report, relevant information from the Denver Metropolitan Area and North Front 

Range (DMAlNFR) 8-hour Ozone State Implementation Plan (SIP) process, the Denver 

Early Action Compact (EAC) process, ambient ozone data for Colorado, ambient ozone 

data for nearby states from the EPA Air Quality System (AQS) database, and other 

information is used to demonstrate that Colorado does not contribute significantly to 

nonattainment in, or interfere with maintenance by, any other state with respect to the 0.08 

ppm ozone NAAQS. 

1 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section I 10 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment 1Air Pollution Control Division 

1.2. Colorado Ozone Monitoring Network 

The 2007/2008 ozone ambient air monitoring network in the Denver area and along the 

northern Front Range consists of 13 stations operated by the Colorado Air Pollution 

Control Division (APCD) and one station operated by the National Park Service (NPS) in 

Rocky Mountain National Park. There have been other stations that have operated in the 

past. The geographical distribution of the Front Range monitors is presented in Figure 1. 

As shown in Figure 1, the ozone monitors are primarily located in urbanized areas along 

the Front Range corridor. The monitors are located in areas where the highest ozone 

concentrations have been monitored historically and where elevated ozone is expected to 

occur. High ozone concentrations along the Front Range occur near the areas with high 

emissions density and dense population. In addition, elevated ozone is observed along 

elevated terrain to the west of the DMA/NFR Nonattainment Area. All of these monitors 

are designated by the U.S. Environmental Protection Agency as "equivalent" analyzers and 

follow all quality assurance requirements as specified in 40 CFR Part 58, Appendix A. 

Ramah .osimla· ,­ - /'9--<:: :: 

Figure I. Location of Front Range Ozone Monitors 

2
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(0)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment I Air Pollution Control Division 

Figure 2 shows other ozone monitoring sites that exist in Colorado for 2008. These are 

operated by either Colorado, the Southern Ute Tribe, or various Federal agencies. All of 

these sites use monitors that are designated as "equivalent" analyzers by the U.S. 

Environmental Protection Agency. As shown, most of the sites are in the southwest comer 

of Colorado, either within or near the San Juan oil and gas development area. 

"N<l"1.1t,.,"",w 

T'~lh.llllK_, ~1\rI101". (" , !l.16Y-'·~

;ipf't<lq1'''~''~" L'!lltll'" 'M Pn1:d'l4't\j.1'So. r ..... h;'QM'l>e'l'l 

~.. "~~~.'v ••. ::~0'1"~~~.:~

~-;~(;~ 0;; -~

Figure 2. Location of Statewide Ozone Monitors 

Table I, Table 2, and Table 3 present the monitoring data for the DMAlNFR NAA 

monitoring sites (including the NPS Rocky Mountain National Park monitoring site) as 

well as for other sites in Colorado. In Table 3, the fourth maximum 8-hour ozone 

concentrations along with the 3-year average of the fourth maximum concentrations at each 

site are presented. As shown in both Table I and Table 3, the Denver area is currently 

meeting the 8-hour and former I-hour ozone NAAQS for all sites, except for the 8-Hour 

NAAQS at Rocky Flats North with a design value of 0.86 ppm. 

3
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table I: 2008 I-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008) 

AQS 

Number Site Name 

1st Max 

I-Hour 

(ppm) 

Date 

1st Max 

I-Hour 

2nd Max 

I-Hour 

(ppm) 

Date 

2nd Max 

I-Hour 

3rd Max 

I-Hour 

(ppm) 

Date 

3rd Max 

I-Hour 

4th Max 

I-Hour 

(ppm) 

Date 

4th Max 

I-Hour 

08-001-3001 Welby 0.100 08/29 0.095 08/05 0.092 07/10 0.089 06/20 

08-005-0002 * Highland 0.065 04/04 0.064 04/08 0.064 04/18 0.062 04/19 

08-013-0011 S. Boulder Creek 0.089 07/10 0.089 07/25 0.086 07/16 0.085 05/31 

08-031-0014 Carriage 0.094 08/05 0.090 08/29 0.089 07/10 0.085 06/20 

08-031-0025 ** Denver - Animal 

Shelter 0.100 07/10 0.098 08/05 0.087 06/20 0.087 08/24 

08-03 5-0004 Chatfield State Park 0.101 07/10 0.098 06/20 0.095 08/29 0.092 08/24 

08-041-00 13 Colo. Spgs. -

Academy 0.085 OS/24 0.083 07/10 0.082 08/06 0.080 07/18 

08-041-0016 Manitou Springs 0.087 OS/24 0.085 08/06 0.083 07/10 0.083 07/11 

08-045-0012 ** Rifle - Health 0.081 07/09 0.080 07/10 0.075 08/19 0.074 07/11 

08-059-0002 Arvada 0.093 08/05 0.093 08/29 0.092 07/10 0.088 07/25 

08-059-0005 Welch 0.102 07/10 0.090 06/20 0.088 08/05 0.088 08/29 

08-059-0006 Rocky Flats - N 0.088 07110 0.088 07/18 0.088 08/29 0.087 07/02 

08-059-0011 NREL 0.097 08/29 0.093 07/10 0.092 08/05 0.092 08/24 

08-067-7001 *** So. Ute -

Ignacio 0.076 06/04 0.075 05/31 0.073 05/03 0.072 05/3 

08-067-7003 *** So. Ute -

Bondad 0.080 06/04 0.078 05/31 0.077 OS/27 0.071 04/21 

08-067-???? USFS - Shamrock 0.081 06/04 0.079 06/10 0.077 02/29 0.077 05/30 

08-069-0007 Rocky Mountain 

Nat'l Park 0.092 07/09 0.090 07/31 0.090 08/28 0.085 OS/22 

08-069-00 I I Ft. Collins - West 0.093 08/19 0.092 07/09 0.092 07/18 0,088 07/24 

08-069-1004 Ft. Collins - CSU 0.082 08/19 0.080 07/09 0.079 08/30 0.078 07/24 

08-077-0020 ** Palisade - Water 0.081 07/09 0.079 07/10 0.075 07/08 0.074 07/05 

08-083-0006 ** Cortez 0.078 07/23 0.074 07/13 0.072 08/05 0.071 07/25 

08-083-0101 Mesa Verde Nat'l 

Park 0.075 05/01 0.075 06/04 0.074 05/31 0.072 04/30 

08-123-0009 Greeley - Weld 

Tower 0.094 08/20 0.092 07/24 0.089 08/01 0.087 08/04 

NOTES: 

* Highland site shut down on 4/21/08 for approx. 6-months.
 

** Denver - Animal Shelter site commenced on 4/22/08, Rifle - Health commenced on 6/20/08,
 

Palisade - Water commenced on 5/30/08 and Cortez commenced on 6/17/08. 

*** Southern Ute sites data only thru 6/30/08. 

4
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table 2: 2008 8-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008) 

AQS 

Number Site Name 

lst Max 

8-Hour 

(ppm) 

Date 

lst Max 

8-Hour 

2nd Max 

8-Hour 

(ppm) 

Date 

2nd Max 

8-Hour 

3rd Max 

8-Hour 

(ppm) 

Date 

3rd Max 

8-Hour 

4th Max 

8-Hour 

(ppm) 

Date 

4th Max 

8-Hour 

08-001-3001 Welby 0.085 07/10 0.083 08/29 0.077 07/18 0.076 06/20 

08-005-0002 * Highland 0.062 04/04 0.060 04/08 0.060 04118 0.059 04/05 

08-013-0011 S. Boulder Creek 0.080 07110 0.076 05/31 0.076 07/09 0.076 07/18 

08-031-0014 Carriage 0.081 07/10 0.075 08/29 0.073 06/20 0.072 07/26 

08-031-0025 ** Denver - Animal 

Shelter 0.086 07/10 0.072 08/29 0.071 07/13 0.070 07/26 

08-035-0004 Chatfield State Park 0.090 07/10 0.082 06/30 0.080 06/20 0.080 06/27 

08-041 -001 3 Colo. Spgs. -

Academy 0.078 OS/24 0.077 07/10 0.073 08/06 0.070 07/18 

08-041 -0016 Manitou Springs 0.080 OS/24 0.076 07/10 0.074 07/11 0.072 07/31 

08-045-0012 ** Rifle - Health 0.076 07/09 0.076 07/10 0.069 08/19 0.066 07/13 

08-059-0002 Arvada 0.081 08/29 0.080 07/10 0.077 06/20 0.074 08/05 

08-059-0005 Welch 0.095 07/10 0.079 06/20 0.077 07/18 0.073 08/19 

08-059-0006 Rocky Flats - N 0.083 07/10 0.080 07/18 0.079 05/31 0.079 08/29 

08-059-0011 NREL 0.085 07/10 0.085 08/29 0.077 06/20 0.076 06/02 

08-067-7001 *** So. UteIgnacio 0.069 06/04 0.067 06/10 0.066 05/10 0.066 06/13 

08-067-7003 *** So. UteBondad 0.073 06/04 0.067 OS/27 0.067 05/31 0.067 06/05 

08-067-???? USFS - Shamrock 0.074 06/04 0.073 06/10 0.071 06/13 0.069 05/30 

08-069-0007 Rocky Mountain 

Nat'l Park 0.081 07/09 0.077 OS/25 0.077 07/31 0.076 05/31 

08-069-00 II Ft. Collins - West 0.081 07/18 0.079 07/09 0.078 OS/25 0.076 07/24 

08-069-1 004 Ft. Collins - CSU 0.070 OS/25 0.070 07/09 0.068 07/18 0.066 05/31 

08-077-0020 ** Palisade - Water 0.077 07/09 0.075 07110 0.070 05/31 0.070 07/29 

08-083-0006 ** Cortez 0.067 08/02 0.066 07/23 0.065 08/07 0.064 08/05 

08-083-0101 Mesa Verde Nat'l 

Park 0.071 06/04 0.070 04/30 0.069 04/21 0.069 06110 

08-123-0009 Greeley - Weld 

Tower 0.077 07/24 0.076 08/20 0.075 07/26 0.073 08/01 

NOTES: 

* Highland site shut down on 4/21/08 for approx. 6-months.
 

** Denver - Animal Shelter site commenced on 4/22/08, Rifle - Health commenced on 6/20/08,
 

Palisade - Water commenced on 5/30/08 and Cortez commenced on 6/17/08. 

*** Southern Ute sites data only thru 6/30/08. 

5
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table 3: Monitored 8-Hour Design Value Using the 3-Year (2006-2008) Average of the Fourth Maximum 

Ozone Concentration 

Site Name AQS# 

2006 

7 

Maximum 

8-Hour 

Average 

Value (ppm) 

2007 

7 

Maximum 

8-Hour 

Average 

Value (ppm) 

2008 

7 

Maximum 

8-Hour 

Average 

Value (ppm) 

Design Value 

(2006 - 2008) 

3-Year 

Average 

4th Maximum 

Value (ppm) 

Welby 08-001-3001 0.069 0.070 0.076 0.071 

• Highland 08-005-0002 0.081 0.075 0.059 0.071 

S. Boulder Creek 08-013-0011 0.082 0.085 0.076 0.081 

Carriage 08-031-0014 0.072 0.076 0.072 0.073 

•• Denver - Animal 

Shelter 08-031-0025 --­ --­ 0.070 ---

Chatfield State Park 08-035-0004 0.086 0.082 0.080 0.082 

USAF Academy 08-041-0013 0.072 0.072 0.070 0.071 

Manitou Springs 08-041-0016 0.076 0.072 0.072 0.073 

•• Rifle - Health 08-045-0012 --­ --­ 0.066 --­

Arvada 08-059-0002 0.082 0.079 0.074 0.078 

Welch 08-059-0005 0.081 0.080 0.073 0.078 

Rocky Flats - North 08-059-0006 0.090 0.090 0.079 0.086 

NREL 08-059-0011 0.083 0.085 0.076 0.081 

••• So. Ute - Ignacio 08-067-7001 --­ --­ 0.066 --­ ••• So. Ute - Bondad 08-067-7003 0.063 0.071 0.067 0.067 

USFS - Shamrock 08-067-1717 0.074 0.069 0.069 0.070 

Rocky Mountain Nat'l 

Park 08-069-0007 0.076 0.078 0.076 0.076 

Fort Collins - West 08-069-00 II 0.087 0.085 0.076 0.082 

Fort Collins - CSU 08-069-1004 0.078 0.069 0.066 0.071 

•• Palisade - Water 08-077-0020 --­ --­ 0.070 --­

•• Cortez 08-083-0006 --­ --­ 0.064 --­

Mesa Verde Nat'l Park 08-083-0101 0.074 0.070 0.069 0.071 

Greeley - Weld Tower 08-123-0009 0.082 0.074 0.073 0.076 

NOTES: 

• Highland site shut down on 4/21/08 for approx. 6-months.
 

•• Denver - Animal Shelter site commenced on 4/22/08, Rifle - Health commenced on 6/20/08,
 

Palisade - Water commenced on 5/30/08 and Cortez commenced on 6/17/08. 

••• Southern Ute sites data only thru 6/30/08. Ignacio data invalid for 0112005 to 08/2007. 

6 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.3. Ozone Monitoring Network in Nearby States 

Table 4 and Table 5 present 8-hour ozone monitoring data from the surrounding states of 

Nebraska, Kansas, New Mexico, Wyoming, and Utah. Table 4 and Table 5 show that none 

of the monitors in surrounding states exceed the 8-hour ozone standard. Therefore, to the 

extent that the network is representative of all areas, it can be concluded that the 

DMAfNFR sources do not significantly contribute to the 8-hour ozone standard violations 

at these down wind locations or even further downwind. 

Table 4: 2005-2007 3-Year Fourth Highest Average Monitoring Concentrations from Kansas, Nebraska, 

New Mexico, Utah and Wyoming (see Table 5 for additional data) 

Site ID State County 

EPA 

Re2ion 

2005 

8-hr 

Ozone 

4th Max 

(ppm) 

2006 

8-hr 

Ozone 

4th Max 

(ppm) 

2007 

8-hr Ozone 

4th Max 

(ppm) 

3-yr 

Avg. of 

4th Max 

(ppm) 

20-045-0004 KS Douglas 7 0.073 0.081 End 2007 N/A 

20-091-0010 KS Johnson 7 0.081 0.076 0.071 0.076 

20-103-0003 KS Leavenworth 7 0.077 0.074 0.080 0.077 

20-107-0002 KS Linn 7 0.075 0.079 0.070 0.074 

20-173-000 I KS Sedgwick 7 0.065 0.065 0.059 0.063 

20-173-0010 KS Sedgwick 7 0.074 0.073 0.060 0.069 

20-191-0002 KS Sumner 7 0.078 0.080 0.070 0.076 

20-195-000 I KS Trego 7 0.071 0.076 0.068 0.071 

20-209-0021 KS Wyandotte 7 0.079 0.081 0.073 0.077 

31-055-0028 NE Douglas 7 0.069 0.072 0.066 0.069 

31-055-0032 NE Douglas 7 0.067 0.066 0.056 0.063 

31-055-0035 NE Douglas 7 0.070 0.067 0.061 0.066 

31-109-0016 NE Lancaster 7 0.056 0.056 0.054 0.055 

35-001-0019 NM Bernalillo 6 0.073 0.073 0.070 0.072 

35-001-0023 NM Bernalillo 6 0.072 0.073 0.069 0.071 

35-001-0024 NM Bernalillo 6 0.074 0.074 0.068 0.072 

35-001-0027 NM Bernalillo 6 0.073 0.072 0.071 0.072 

35-001-0029 NM Bernalillo 6 0.071 0.070 0.067 0.069 

35-001-1012 NM Bernalillo 6 0.077 0.047 0.074 0.066 

35-001-1013 NM Bernalillo 6 0.077 0.071 0.071 0.073 

35-001-1014 NM Bernalillo 6 0.072 0.072 0.064 0.069 

35-013-0008 NM Dona Ana 6 0.070 0.072 0.068 0.070 

35-013-0017 NM Dona Ana 6 0.070 0.073 0.070 0.071 

35-013-0020 NM Dona Ana 6 0.072 0.072 0.068 0.070 

35-013-0021 NM Dona Ana 6 0.076 0.080 0.076 0.077 

35-013-0022 NM Dona Ana 6 0.070 0.073 0.073 0.072 

35-013-0023 NM Dona Ana 6 0.066 0.070 0.062 0.066 

7 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table 5. 2005-2007 3-Year Fourth Highest Average Monitoring Concentrations from Kansas, Nebraska, 

New Mexico, Utah and Wyoming (see Table 4 for additional data) 

Site ID State County 

EPA 

Re~ion

2005 

8-hr 

Ozone 

4th Max 

(ppm) 

2006 

8-hr 

Ozone 

4th Max 

(ppm) 

2007 

8-hr Ozone 

4th Max 

(ppm) 

3-yr 

Avg. of 

4th Max 

(ppm) 

35-015-1005 NM Eddy 6 0.067 0.076 0.066 0.069 

35-017-1003 NM Grant 6 0.071 0.067 0.062 0.066 

35-025-0008 NM Lea 6 0.074 0.075 0.064 0.071 

35-029-0003 NM Luna 6 Start 2006 0.053 0.062 N/A 

35-043-1001 NM Sandoval 6 0.069 0.064 0.063 0.065 

35-043-1003 NM Sandoval 6 0.075 0.074 0.071 0.073 

35-043-9004 NM Sandoval 6 0.076 0.072 0.067 0.071 

35-045-0009 NM San Juan 6 0.075 0.063 0.069 0.069 

35-045-0018 NM San Juan 6 Start 2006 0.079 0.079 N/A 

35-045-1005 NM San Juan 6 0.072 0.071 0.073 0.072 

49-003-0003 UT Box Elder 8 0.079 0.078 0.077 0.078 

49-003-7001 UT Box Elder 8 0.075 0.076 0.078 0.076 

49-005-0004 UT Cache 8 0.069 0.073 0.074 0.072 

49-011-0004 UT Davis 8 0.092 0.082 0.082 0.085 

49-035-0003 UT Salt Lake 8 0.083 0.084 0.082 0.083 

49-035-2004 UT Salt Lake 8 0.086 0.082 0.082 0.083 

49-035-3006 UT Salt Lake 8 0.082 0.082 0.079 0.081 

49-035-3007 UT Salt Lake 8 0.085 0.080 0.080 0.081 

49-035-3008 UT Salt Lake 8 0.080 0.082 0.079 0.080 

49-037-0101 UT San Juan 8 0.069 0.070 0.072 0.070 

49-045-0003 UT Tooele 8 0.080 0.079 0.076 0.078 

49-049-0002 UT Utah 8 0.078 0.074 0.075 0.075 

49-049-5008 UT Utah 8 0.080 0.077 0.078 0.078 

49-049-5010 UT Utah 8 0.080 0.079 0.077 0.078 

49-053-0130 UT Washington 8 0.091 0.072 0.071 0.078 

49-057-0007 UT Weber 8 0.081 0.083 0.080 0.081 

49-057-1003 UT Weber 8 0.084 0.083 0.082 0.083 

56-005-0123 WY Campbell 8 0.063 0.072 0.072 0.069 

56-005-0456 WY Campbell 8 0.063 0.065 0.072 0.066 

56-035-0098 WY Sublette 8 0.075 0.069 0.068 0.070 

56-035-0099 WY Sublette 8 0.079 0.072 0.067 0.072 

56-035-0100 WY Sublette 8 0.066 0.074 0.066 0.068 

56-037-0200 WY Sweetwater 8 Start 2006 0.067 0.064 N/A 

56-039-1011 WY Teton 8 0.060 0.069 0.065 0.064 

Figure 3 presents a map of all the U.S. nonattainment areas. Since the surrounding states 

of Kansas, Nebraska, Wyoming, Utah, and New Mexico do not have violations the 8-hour 

NAAQS for ozone, it can be reasonably concluded that Colorado sources do not 

significantly affect the ozone nonattainment areas even further downwind such as Dallas8
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment I Air Pollution Control Division 

Forth Worth and 81. Louis nonattainment areas. In addition, it is unlikely that Colorado 

would significantly affect nonattainment areas that are typically "upwind" such as Las 

Vegas and Phoenix. However, it is recognized that, under the types of synoptic scale 

meteorological regimes that occur during some regional ozone episodes, simple terms like 

"upwind" and "downwind" may not be applicable. Thus, photochemical modeling is 

needed to study the distribution of ozone under a variety of meteorological regimes. 

Nonattainment and Maintenance Areas in the U. S. 

8-hour Ozone Standard 

J' 

\ 

'~\-.- ........ '-... ·..v,...~"'-:~/

\ ""::~:i-,/.r~~ ._~.----~~~~

) ""-'V',,');~"\ t {' "J 

. i!f\ 

·,-··r'· \,,- \u ..••1. " 'j. \ . . ;-~-. - ----A...- __, " ,. ..< 

.. ~_ \. --( ,
 \ '\1 •. ~,,~\lllilv_'~<, /" ·:"k.':tf
 \, r-·.. (;..../f' )'....".-,,. _ >"'~

~~~,,-_~'_~- ,:'-- ~--.~LlSf,~~Z~>l
 wmoo 

" \,. ( .. '.- ••, ~'--'" -\l~ '-'-. ..?",._lr:.»--.... r', '. \\ ( -,-t; """'. " ,.:/'~'_.""""-" .,-._~.s~">.~"r';' '""""~

..Nonattainment Areas (263 entire counties) \ '... >.
 .... Nonattainment Areas (30 partial counties) \ ......
 

i Maintenance Areas (141 entire or partial countles)\,.:\
 

Partial counties, those with part of the county designated
 

nonattainment and art attainment, are shown as fun counties on the ma .
 

."". 

.,Jf. "i 

Figure 3: 8-Hour Ozone Nonattainment Areas 

9
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.4.	 Ozone Transport Conclusions from the DMA/NFR 

Photochemical Modeling 

The DMAlNFR photochemical model domain was defined on a nested 36-kilometer (km), 

12 km, and a 4 km nested-grid structure. This structure was utilized in conjunction with 

the Comprehensive Air-quality Model with extensions (CAMx) air quality model 

(ENVIRON, 2008). CAMx, SMOKE (Coats, 1996), and CONCEPT MS (Loomis et aI., 

2005) air quality and emissions modeling was performed for the June-July 2006 period. 

Nested 36/12/4 km modeling domains were used in the Denver 8-hour ozone modeling 

study. The CAMx model was first applied to the 36 km continental U.S. domain using 

boundary conditions (BCs) from a global climate air quality model. The CAMx 2006 and 

2010 base case modeling results from the 36 km continental U.S. domain simulation were 

then processed to generate BCs for the CAMx 12/4 km domain (Figure 4) for the 2006 12/4 

km base case and 2010 12/4 km base case and sensitivity simulations. The CAMx 

simulations for the 12/4 km domains were run using two-way interactive grid nesting (i.e., 

pollutants can flow back and forth between the 12 km and 4 km domains to account for 

recirculation). The larger 36km domain was selected to address the impact of boundary 

condition uncertainties for the Front Range area of Colorado, as APCD was concerned 

there may be transport from Southern California and Texas. The 12 km grid resolution 

domain essentially covers the central Rocky Mountain States or portions thereof (i.e., 

Arizona, Colorado, New Mexico, Utah and Wyoming.) The 4 km nested-grid covers most 

of the state of Colorado. 

480 I 

J 

360 ( 1--- ­ - -.,'	 l 

r I , I 240 

120­

o 

-120 

-240 

/ L----T--- --.------L=t~	 \,' j 

I i : ! I 

, 

! 

i , 

, ;'A __ 

\" r ,j	 -.L.. CAMx 4~m ' 

:::" J' j	 ; l CAM' 12k: I" ',',' " ' 'I' "! 'I 'I' ' , ""I', 

-1680-1560-1440-1320-1200-1080 -960 -840 -720 -600 -480 ·360 -240 -120 0 120 240 

Figure 4. Nested 12/4 km modeling domains for the Denver CAMx air quality and SMOKE emissions 

modeling. 

10 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.4.1. Emission Inventories and 2006 and 2010 Base Case 

The photochemical modeling for the "2010 base case" emissions scenario performed for 

the DMAINFR Ozone SIP process demonstrates compliance in the Front Range Region 

with the 8-hour 0.08 ppm ozone NAAQS. Control measures in place in 2006 and assumed 

for 2010 include: 

1.	 Federal tailpipe standards and regulations, including those for small engines and 

non-road mobile sources. Credit is taken for these federal requirements but they are 

not part of the Colorado SIP. The credits change from 2006 to 2010 as the United 

States Environmental Protection Agency (EPA) Tier II and low sulfur gasoline 

standards become effective. 

2.	 Air Quality Control Commission Regulation No. ll--covering the Automobile 

Inspection and Readjustment (A.I.R.) program in place during the 2006 ozone 

season, which includes an enhanced InspectionlMaintenance (11M). For 2006, a 

maximum of 10% fleet coverage is assumed, and for 2010, a maximum of 50% 

fleet coverage is assumed for the remote sensing clean screen program in the 

Denver metro area (DMA) based on Regulation No. 11. 

3.	 Air Quality Control Commission Regulations No.3, No.6, No.7, and Common 

Provisions--covering gasoline station and industrial source control programs. The 

Common Provisions, Parts A and B of Regulation No.3, and the volatile organic 

compounds (VQC) control requirements of Regulation No.7 are already included 

in the approved SIP. Regulation No.6 and Part C of Regulation No.3 implement 

the federal standards of performance for new stationary sources and the federal 

operating permit program. This reference to Regulation No.6 and Part C of 

Regulation No.3 shall not be construed to mean that these regulations are included 

in the SIP. 

4.	 Since 2004, gasoline sold in the Denver metro area during the summer Reid Vapor 

Pressure (RVP) ozone season (June 1 to September 15) has been subject to a 

national RVP limit of 7.8 pounds per square inch (psi) to reduce fuel volatility. For 

ethanol-blended fuels, the RVP limit is 8.8 psi due to the federal 1.0 psi RVP 

waiver for ethanol. 

Since 1991, gasoline sold in the Larimer and Weld area during the summer ozone 

season (June 1 to September 15) has been subject to a national RVP limit of9.0 psi 

to reduce fuel volatility. For ethanol-blended fuels, the RVP limit is 10.0 psi due to 

the federal 1.0 psi RVP waiver for ethanol. 

For 2006, the RVP of gasoline for the Denver metropolitan portion of 

nonattainment area was determined by survey to be at 8.2 psi, with an ethanol 

market share of 60%, and for the Larimer and Weld portion of the nonattainment 

area the RVP was determined to be 8.4 psi with the same ethanol share of 60%. For 

purposes ofthe base case 2010 mobile source inventory, the RVP of the base 

11
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

gasoline is assumed to be 7.8 psi for the Denver metropolitan portion of 

nonattainment area, with an ethanol market share of 85%, and for the Larimer and 

Weld portion of the nonattainment area the RVP was assumed to be 9.0 psi with an 

ethanol share of 25%. 

5.	 The EPA approved the EAC Ozone Action Plan (OAP) on August 19,2005. The 

OAP included an amendment to Regulation No.7 requiring the reduction of flash 

emissions of volatile organic compounds from condensate collection, storage, 

processing and handling operations by May 1,2005. This initial rule required the 

installation of air pollution control technology to achieve a system-wide 47.5% 

reduction from uncontrolled emissions of volatile organic compounds from new and 

existing oil and gas exploration and production operations located within the 8-hour 

ozone nonattainment area designated by EPA for operators with total emissions 

greater than 30 tons per year. The 2006 base case estimate was developed from 

actual reported emissions based on the system-wide 47.5% reduction requirement. 

6.	 In February 13,2008, the EPA approved revisions to Regulation No.7 to require 

the system-wide reduction of condensate tank flash VOC emissions of 75% for the 

2007 ozone season by May 1, 2007 and 78% reduction for the 2012 ozone season, 

with technology that achieves a 95% reduction in VOC emissions. The 2010 base 

case emissions estimate assumes the 75% system-wide reduction requirement. 

7.	 The effect of EPA final locomotive Tier 3 standards were considered and included, 

where appropriate, in the 2010 area source estimates. Tier 4 10comotive standards 

do not go into effect until 20 15 and therefore were not included in the 2010 

inventories. 

All of the inventories in this 8-hour Ozone Attainment SIP were developed using EPA 

approved emissions modeling methods, including EPA's MOBlLE6 model and local VMT 

data for on-road mobile source emissions, EPA's non-road model and local demographic 

information for area and off-road sources, and reported actual emissions for point sources. 

Estimates for future emissions are based on the above-mentioned tools and the EPA's 

Economic Growth and Analysis System (EGAS) model for estimating future point sources 

activity, VMT growth for on-road mobile sources, and 2010 and 2012 demographic data 

for off-road and area sources. The technical support document contains detailed 

information on model assumptions and parameters for each source category. 

Highway mobile source emissions are from the ENVIRON Consolidated Community 

Emissions Processing Tool (CONCEPT) model inventory, which is based on DRCOG 

VMT data and MOBILE6 input data provided by APCD and expanded to the entire NAA 

based on VMT from the North Front Range Transportation and Air Quality Planning 

Council and CDOT. 

Non-road source emissions are from the EPA Non-Road Model. This model includes the 

impact of future controls on non-road engines, which is used in equipment such as lawn 

and garden equipment and construction equipment. Oil and gas source emissions are from 

12
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment I Air Pollution Control Division 

the revised Independent Petroleum Association of Mountain States (IPAMS) inventory, 

and were projected to 2010 using the methodology in the IPAMS projection methodology 

document. The IPAMS inventory was sponsored by the IPAMS and is Phase III of a 

regional oil and gas emission inventory for the Inter-Mountain West jointly with the 

Western Regional Air Partnership (WRAP). 

Non-oil and gas area source emissions (including heating, consumer solvent use, aircraft 

and railroads, etc.) are from the 2002 EPA National Emissions Inventory (NEI), grown to 

2006 and 2010 by population growth from data from the State Demographer. Consumer 

solvent emission reductions based on 75% of the per-person reductions listed in the EPA 

May 30, 2007 Emission Reduction Credit Memo were applied to the projected 2010 nonoil and gas area source inventory. A check on the non-oil and gas area sources estimates 

comparing the recently available 2005 NEI emissions data is shown later in this document. 

An inventory completed in 2005 for Denver International Airport (OIA) was used for 

aircraft and airport non-road source emissions from DIA for both 2006 and 2010. 

Non-oil and gas point source emissions were grown to 2010 by the EPA EGAS economic 

model, and by adding sources for which permits have been issued. 

Emissions ofVOC and nitrogen oxides (NOx) from biogenic sources have been generated 

by the Model of Emissions of Gases and Aerosols from Nature (MEGAN) Biogenic 

Emissions Model using land cover data base of biomass type and density and hourly 

meteorology data. The National Center of Atmospheric Research (NCAR) has produced a 

global data base ofland use data, the MEGAN Driving Variable Database Version 1.2, for 

use with MEGAN. Surface temperatures are provided by the Mesoscale Meteorological 

Model (MM5) modeling. 

Summaries of the VOC and NOx base case inventories for the nonattainment area for 2006 

and 2010 are presented in Table 6. Emissions of NOx and VOCs are in tons per average 

episode day. Additional detail on the categories of emissions can be found in the TSO. 

Wildfire emissions, though not included in tables, have been considered for the background 

ozone concentrations in the modeling effort. Wildfire emissions can vary significantly on a 

day-to-day basis depending on conditions. 

13 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table 6. Base Case Inventories for 8-Hour Ozone DMAINFR NAA Photochemical Modeling 

(tons per average episode day) 

2006 2010 

Source eateaory NOx: voe . NOx : voe 

· · Point Sources 

Electric Generation Units (EGU) 55.6 0.7 58.5 : 1.6 

External Combustion Boilers 9.5 0.4 10.0 1 0.5 

Industrial Processes 12.5 10.2 14.0 : 11.0 

Petroleum and Solvent Evaporation 0.3 19.0 0.3 : 22.0 

Other 3.1 1.8 36: 2.0 

Point Sources Subtotal 81.0 32.1 86.4 37.0 

Oil & Gas Point & Area Sources 

Condensate Tanks 126.5 129.6 

Other O&G Point Sources 22.6 6.8 23.6 8.6 

Pneumatic Devices (Area Source) 24.8 31.1 

Unpermitted Fugitives (Area Source) 16.2 20.4 

Other Area Sources 17.1 10.8 22.5 137 

O&G Point & Area Sources Subtotal 39.7 185.2 46.2 203.3 

Area Sources 

Personal Care Products 7.1 7.0 

Household Products 21.4 17.9 

Automotive Aftermarket Products 11.9 13.0 

Architectural Coatings 20.1 16.8 

Aircraft 7.4 1.3 8.2 . 1.5 

Railroad 12.8 05 13.8 0.6 

Other CoatingslPesticides/Cooking/ Miscellaneous. 3.9 41 

Area Source Subtotal 20.2 66.3 22.1 61.0 

Non-Road Mobile Sources 

Agricultural Equipment 70 0.9 6.3 0.7 

Airport EqUipment 0.7 0.1 0.6 0.1 

Commercial Equipment 5.3 6.2 5.1 7.0 

Construction and Mining Equipment 35.7 5.5 31.2 4.5 

Industrial Equipment 10.5 2.4 6.9 1.4 

Lawn and Garden EqUipment (Commercial) 9.4 35.9 8.9 281 

Lawn and Garden Equipment (Residential) 1.2 7.5 1.2 11.8 

Boats/Recreational EquipmenUMiscellaneous 07 6.9 0.8 78 

Non-Road Mobile Source Subtotal 70.5 65.3 

1655 129.7 

165.5 129.7 

376.8 478.6 

53.0 694.0 

429.8 1172.6 

61.0 61.3 

1229 : 109.2 

122.9 : 109.2 

338.5 : 471.8 

53.0 : 694.0 

· 391.5 : 1165.8 

On-Road Mobile Sources 

On-Road Mobile (including vehicle refueling) 

On-Road Mobile Subtotal 

Anthropogenic Total 

Biogenic Total 

Anthropoaenic & Bioaenic Total 

14 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section I IO (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.4.2. Discussion of 2010 Base Case CAMx Modeling Results 

Currently, Colorado's highest emissions density is along the Front Range. As shown in 

Figure 5 Photochemical Modeling done for the DMA/NFR SIP process shows that the 

highest 2010 ozone design values along the foothills west of Denver and Fort Collins. 

Ozone concentrations decrease rapidly to the east of Denver. The maximum projected 2010 

base case 8-hour ozone Design Value of 84 ppb occurs at both the Rocky Flats North and 

Fort Collins West monitoring sites. As this value is 84 ppb or lower, the 2010 base case 

modeling results pass the EPA modeled attainment demonstration test. Although the EPA 

8-hour ozone projection procedure is to truncate the final projected DVF for comparisons 

with the NAAQS, the projected 2010 base case future years design value is 84.9 ppb 

(Morris, et aI, 2008a). 

.' "*Itt ~._', ..... 

/"0 

l- b::~':f.,,;,)

, Oerwet1l4km_dorn_OV 

- ---, , --1 BASE DVF

-

l1li 

Figure 5. Projected 2010 8-hour ozone Design Values (DVF) 

Figure 6 presents the ozone source apportionment results, including the boundary 

conditions. The boundary conditions (BCs) show the contribution from sources outside the 

12 km domain (see Figure 4) for a given high ozone day (results vary by day). On this day, 

15
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

of the 76.1 ppb of ozone estimated at the monitor, approximately 48 ppb was transported 

into the 12 km domain and approximately 8 ppb was attributed to sources in the sevencounty Denver Metro area (Morris, et aI, 2008a) while the rest was from other counties in 

Colorado or from other states. This suggests that, on this day, ozone was generated 

primarily by global/continental scale "background" and local sources of emissions in the 

Denver Metro area. Transport from nearby states was relatively small. 

runl6c.osaUy20 10.1204
 

060729 (2006210)
 

Metric-03M Average >= 70.0 PPB
 

Total Ozone 76.1 (ppb) - Receptor rfno
 

72 

64 

56 

.-.. 

.0 

p.. 

8 

48 

<) 40 

0 

u 

<l! 

Q 

0 

t'l 

0 

32 

24 

Ie !!II!I Be 

• EGU 

• NonEGU lIlII! Area 

OiIGas 

• Nonroad 

Motor Veb. 

- BioFire 

16 

8 

(L	 ,...,e..-_--._~ 	 __ 0 

g; 23 o o 00+ + L> L>	 

+	 '-' r.:I N	 l:Il rn [II z E-< ..: OSAT Source Regi8bs 

Figure 6. Rocky Flats North source apportionment for 29 July including boundary conditions. 

Conclusions from ozone source apportionment results (Morris, et aI, 2008a) vary by day 

and by location. However, several overall trends emerged, namely: 

•	 Regional ozone transport into the 12 km domain is the largest contributor, often 

accounting for more than two-thirds of the total ozone; 

•	 At the Denver Metropolitan monitors the largest contributors are Denver
 

Metropolitan metro area motor vehicle and non-road sources;
 

•	 At the Fort Collins and Greeley monitors, the largest contributors tend to be 

Larimer and Weld County motor vehicles, non-road sources and oil and gas 

sources, and Denver Metropolitan sources; 

•	 The majority of the ozone formed is attributable to anthropogenic NOx emissions. 

16
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

In interpreting these results, it is important to keep in mind that the source apportionment 

results are based on the Denver SIP 2006 modeling episode and are meteorologically 

dependent For instance, the source apportionment modeling in support of the Denver 

Early Action Compact using a 2002 ozone episode (Morris, et aI, 2004a) showed more 

impact from sources in northern Colorado in the Denver Metropolitan area. 

Other ozone transport studies also confirm that Denver is impacted by ozone from areas 

well outside of Colorado. A report sponsored by the Western States Air Resources Council 

(WESTAR) indicates that, when ozone is greater than 85 ppb in Denver, natural 

background accounts for 37.5% of the total concentration, transported anthropogenic 

generated ozone is 37.5%, and the local anthropogenic ozone contribution is about 25% 

(MacDonald, et. aI, 2006). 

A common theme at all ozone monitors is that a majority of the peak 8-hour ozone is due to 

ozone transport from sources outside of Colorado and outside the 12km domain boundary. 

Source apportionment modeling indicates that transport into the region accounts for 

approximately 60-75% of the ozone formation in the DMAINFR. This indicates that the 

DMAINFR is more of a receptor of ozone and ozone precursors rather than a producer of 

ozone and precursors that transports ozone to areas outside of the Front Range. While the 

modeling suggests that the transport of ozone and/or ozone precursors is a significant issue 

in the west, the magnitude of ozone transport from Colorado to other states is too low to 

significantly contribute to nonattainment in, or interfere with maintenance by, any other 

state with respect to the 0.08 ppm ozone NAAQS. 

17 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.5.	 Denver Metro Area/North Front Range Ozone Nonattainment 

Area Contribution to Downwind Locations 

As part of the Denver EAC, source apportionment modeling was conducted to evaluate the 

spatial extent of the 8-hour ozone impacts due to emissions from various source regions in 

Colorado. A similar analysis was not done as part of the DMA/NFR ozone SIP analysis, 

however, a similar conclusion would be expected. The conclusion is that ozone formed 

specifically from sources in the DMA/NFR nonattainment area decreases rapidly in 

concentration over the eastern plains of Colorado. Therefore, the photochemical modeling 

that was done for both the DMA/NFR ozone SIP and the Denver EAC suggest that ozone 

and/or ozone precursors from the Front Range do not contribute significantly to downwind 

monitors in other states. 

Figure 7 displays the spatial extent of the 8-hour ozone concentrations that occurred 

between 10am and 6pm local time (the time when the daily maximum 8-hour ozone 

typically occur) on June 27, 2002 through July 1,2002 due to all emissions (anthropogenic 

and biogenic) from the DMA. As shown in Figure 7, which represents a high ozone 

episode in Denver, the DMA can contribute approximately 10 ppb of ozone at the eastern 

border of Colorado. However, the concentration gradient falls off quickly and emissions 

from the DMA are not expected to be a significant contributor to any ozone nonattainment 

area downwind of the Front Range. Weld, Elbert, Morgan, Larimer, EI Paso and other 

counties contribute even less ozone to the Colorado border states with a maximum 

contribution of 5-10 ppb. 

18
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

10-000 

$.000 

0,000 I 

PPB 

Conlribulions 10 S·h,' Owne 

0.000 1 PI'S 

Cont1"ibution~10 g·h" (hone 

from Denver M'tropolilan Hllil C.AAl>< '.~.02lOOl <nll4l12.3grd 

Contributions 10 8-hr Ozone 

''''>Im [lflW'I' ~tll i)JlnHu.'"l ~\t\!'.

CAM''oI'10~ 1001 cntl4...."'grd 

~un, 29.2002 10:00 :00 fbn' 0.000 '1(1.00PM.< 18.!J8 "(~'12<l1

lD.OOO 60 

lS.00D 

10,000 

S.OOO 

OW, I 1'1'11 

Contdbutions 10 g-hl' Ozone 

from Dvnvvr ~"t"pO'Utt&n An,. rAr.A:< "'1l21OO7~nll4 .....:lgrd 

.)w,. 302002 10100:00 

lAin ·H.oo at(l.oo. M",,· 17.5~ or (71....' 

Contributions to 8-hr 01.One 

1rorn D,mv~r t<·'ktn:)pulitan An" CAt,~)l: 'o'4co17i:JOI clltl..".-.2.lIgrd 

?\J.Don .. .---~--------7"'.

'5.000 

Hl.aDO 

~; 0,000 1 

rra 

0. 

t~"i.:

July 1.""02 10:00'00 .
 Min... O.oOO;i'(l_:)R).M~ 7.8.211 at(:l6;J3
 

Figure 7: Spatial extent of the 8-hour ozone concentrations that occurred between lOam and 6pm local time 

on June 27, 2002 through July 1,2002 

19
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.6. Section 11 O(a)2 - Ozone Transport Conclusions 

With respect to the 0.08 ppm ozone NAAQS, emission control programs in the Colorado 

SIP are expected to adequately protect neighboring states from interstate transport of 

ozone, per Clean Air Act (CAA) Section II 0(a)(2)(D)(i). 

Ambient monitoring data in and around Colorado support the assertion that Colorado does 

not contribute significantly to nonattainment in, or interfere with maintenance by, any other 

state with respect to the 0.08 ppm ozone NAAQS. Specifically: 

1.	 A review of recent ozone observations from the EPA AQS database shows that, 

with the exception of a single monitor in Jefferson County, Colorado (i.e., Rocky 

Flats North), all monitoring sites in Colorado and adjacent states that are likely to 

be impacted by Colorado demonstrated attainment of the 0.08 ppm 8-hour ozone 

NAAQS for the three year period of 2005-2007. Since ozone monitors in adjacent 

states comply with the 0.08 ppm NAAQS, it logically follows that Colorado does 

not cause or contribute to monitored violations or interfere with maintenance of the 

0.08 ppm ozone NAAQS in any other state. 

2.	 For Rocky Flats North, which is the only monitor in Colorado that has levels above 

the 0.08 ppm ozone NAAQS, the preliminary three-year average (2006-2008) 

fourth high value is 0.086 parts per million (ppm), which is only slightly above the 

0.08 ppm ozone NAAQS. 

3.	 Observations from current networks show that the highest ozone levels in Colorado 

occur along the Colorado Front Range and not in other areas of Colorado. 

4.	 Ozone monitoring data from the surrounding states that are most likely to be 

impacted by Colorado (i.e., Nebraska, Kansas, New Mexico, Wyoming, and Utah) 

show that none of the monitors exceed the 0.08 ppm 8-hour ozone standard. Since 

the areas represented by these monitors are in monitored attainment, it is highly 

unlikely that existing 0.08 ppm ozone nonattainment areas beyond these areas are 

significantly affected by emissions from Colorado. The nearest 0.08 ppm ozone 

nonattainment areas to DMAlNFR Nonattainment Area are: 

a.	 Phoenix, Arizona (Basic Area for 8-Hour ozone) at a distance of 586 miles; 

b.	 Las Vegas, Nevada (Basic Area for 8-hour ozone) at a distance of628 

miles; 

c.	 Dallas, Texas (Moderate 8-hour ozone nonattainment area) at a distance of 

663 miles; and 

d.	 St. Louis, Missouri (Moderate 8-hour ozone nonattainment area) at a 

distance of 796 miles. 

Photochemical modeling and other technical analyses performed for the Denver Early 

Action Compact (EAC) and the Denver Metro Area and North Front Range (DMAlNFR) 

8-hour Ozone SIP support the assertion that Colorado does not contribute significantly to 

20 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment I Air Pollution Control Division 

nonattainment in, or interfere with maintenance by, any other state with respect to the 0.08 

ppm ozone NAAQS. Specifically: 

1.	 The Denver 8-hour Ozone SIP photochemical modeling for 2010 and the associated 

weight of evidence analyses suggest that the DMAlNFR nonattainment area and 

downwind areas already comply or will comply with the 0.08 ppm ozone NAAQS 

by 2010. 

2.	 Photochemical modeling shows that elevated ozone concentration levels generated 

from local emissions decrease rapidly with distance. 

3.	 A review of photochemical modeling performed for both the DMAlNFR Ozone SIP 

and the Denver EAC, including boundary condition analyses, suggests that the 

magnitude of ozone transport from Colorado to other states is too low to 

significantly contribute to nonattainment in, or interfere with maintenance by, any 

other state with respect to the 0.08 ppm ozone NAAQS. 

In summary, a review of monitoring data, photochemical modeling, and weight of evidence 

analyses generated for the DMAINFR SIP process suggests that the transport of ozone and 

ozone precursors from Colorado does not cause or significantly contribute to nonattainment in, 

or interfere with maintenance by, any other state with respect to the 0.08 ppm 8-hour ozone 

NAAQS. This analysis does not address ozone transport for the revised 0.075 ppm 8-Hour . 

Ozone NAAQS. 

21
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

2. REFERENCES 

Coats, C.l. Jr. "High-performance algorithms in the Sparse Matrix Operator Kernel Emissions 

(SMOKE) modeling system." Proc. Ninth AMS Joint Conference on Applications ofAir 

Pollution Meteorology with AWMA. Amer. Meteor. Soc., Atlanta, GA, 584-588. 1996. 

ENVIRON. User's Guide - Comprehensive Air Quality Model with Extensions - Version 

4.40. ENVIRON International Corporation, Novato, CA http://www.camx.com. February 

2008. 

Loomis, C., l. Wilkinson, J. Haasbeek, A. Pollack and M. Jansen. 2005. "ConCEPTConsolidated Community Emissions Processing Tool, An Open-Source Tool for the Emissions 

Modeling Community." Presented at the 14th International Emission Inventory Conference 

"Transfonning Emission Inventories - Meeting Future Challenges Today", Las Vegas, 

Nevada, April 11- 14. <http://\vww.epa.gov/ttn/chieflconferencc/ci14/sessionlllloomis.pdf> 

MacDonald, C., Miller, D., Raffuse, S., 2006. Regional and Local Contributions to Peak Local 

Ozone Concentrations in Six Western Cities. Sonoma, Technology, Inc., Petaluma, CA. 

Prepared for WESTAR Council of Governments.. May 16 

Morris R, E. Tai, Tanarit Sakulyanontvittaya, D. McNally and C. Loomis. 2008a. 2010 Ozone 

Projections for the 2010 Base Case and 2010 Sensitivity Tests and 2010 Ozone Source 

Apportionment Modelingfor the Denver 8-Hour Ozone State Implementation Plan. ENVIRON 

International Corporation, Novato, California. Prepared for Denver Regional Air Quality 

Council (RAQC), Denver, Colorado. September 8. 

Morris R, E. Tai, Tanarit Sakulyanontvittaya, D. McNally and C. Loomis. 2008b. 2010 Ozone 

Attainment Demonstration Modelingfor the Denver 8-Hour Ozone State Implementation Plan 

Control Strategy. ENVIRON International Corporation, Novato, California. Prepared for 

Denver Regional Air Quality Council (RAQC), Denver, Colorado. September 22. 

Morris, RE., G.E. Mansell, E. Tai, D.A. McNally and T.W. Tesche. 2004a. Air Quality 

Modeling Analysisfor the Denver Early Action Compact: Ozone Source Apportionment 

Modelingfor the Denver EAC. Prepared for the Colorado Department of Health and 

Environment and Denver Regional Air Quality Council, Denver, Colorado. Prepared by 

ENVIRON International Corporation, Novato, CA. May 31 .. 

22
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Statement of Basis, Specific Statutory Authority and Purpose 

THIS STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND PURPOSE SUPPORTS REVISIONS 

TO COLORADO'S IMPLEMENTATION PLAN REGARDING THE INTERSTATE TRANSPORT OF AIR 

POLLUTANTS (HEREINAFTER "INTERSTATE TRANSPORT SIP"). THESE REVISIONS APPLY TO 

COLORADO'S STATE IMPLEMENTATION PLAN ONLY AND DO NOT REVISE ANY REGULATION. 

THEREFORE, THIS STATEMENT IS NOT REQUIRED BY THE ADMINISTRATIVE PROCEDURES ACT. 

NEVERTHELESS, THE COMMISSION OFFERS THIS STATEMENT TO FURTHER THE UNDERLYING 

OBJECTIVES OF THE APA AND THE COLORADO AIR POLLUTION PREVENTION AND CONTROL ACT. 

BASIS 

THE AIR QUALITY CONTROL COMMISSION HAS ADOPTED REVISIONS TO THE INTERSTATE 

TRANSPORT SIP TO ADDRESS COMMENTS FROM THE UNITED STATES ENVIRONMENTAL 

PROTECTION AGENCY (EPA) FINDING THE SIP DEFICIENT. 

IN FEBRUARY OF 2007 THE COMMISSION ADOPTED AN INTERSTATE TRANSPORT SIP FOR OZONE 

AND PM2.5. THIS SIP WAS TRANSMITTED TO EPA IN JUNE OF 2008. SINCE THAT SIP PRECEDED 

THE 2007 OZONE SEASON, IT DID NOT REFLECT THE MONITORING RESULTS FROM THAT PERIOD, 

INCLUDING THE VIOLATION OF THE 1997 GROUND-LEVEL OZONE NATIONAL AMBIENT AIR 

QUALITY STANDARDS (NAAQS) AND EPA's SUBSEQUENT DESIGNATION OF NONATTAINMENT FOR 

THE DENVER METRO AREA AND NORTH FRONT RANGE (DMAINFR). EPA OFFERED INFORMAL 

COMMENTS ON THE INTERSTATE TRANSPORT SIP, OPINING ON THIS AND OTHER PERCEIVED 

DEFICIENCIES. IN RESPONSE, THE COMMISSION ADOPTED THE FOREGOING REVISIONS TO ADDRESS 

DEFICIENCIES PERTAINING TO OZONE. 

STATUTORY AUTHORITY 

THE STATUTORY AUTHORITY FOR THESE REVISIONS IS SET FORTH IN § 25-7-105(1), c.R.S. OF THE 

COLORADO AIR POLLUTION PREVENTION AND CONTROL ACT ("ACT"), WHICH AUTHORIZES THE 

COMMISSION TO ADOPT A STATE IMPLEMENTATION PLAN THAT MEETS ALL REQUIREMENTS OF THE 

CLEAN AIR ACT. 

PURPOSE 

THE PURPOSE OF THIS INTERSTATE TRANSPORT SIP REVISION IS TO ADDRESS EPA COMMENTS 

THAT THE SIP DOES NOT ADEQUATELY ADDRESS ANY ADVERSE IMPACTS THE DMAlNFR NONATIAINMENT AREA MA Y HAVE ON OTHER STATES' COMPLIANCE WITH THE OZONE NAAQS. 

PURSUANT TO 42 U.S.C. § 741O(A)(2)(D)(I), COLORADO'S INTERSTATE TRANSPORT SIP MUST 

DEMONSTRATE, AMONG OTHER THINGS, THAT COLORADO'S AIR POLLUTION SOURCES WILL NOT 

CONTRIBUTE SIGNIFICANTLY TO NONATTAINMENT, OR INTERFERE WITH MAINTENANCE BY, ANY 

OTHER STATE OF THE OZONE NAAQS. THE COMMISSION HAS REVISED THE OZONE TRANSPORT 

SECT10N OF THE INTERSTATE TRANSPORT SIP TO INCLUDE ANAL YSIS, MONITORING AND MODELING 

INFORMATION DEMONSTRATING THAT COLORADO, INCLUDING THE DMAlNFR NON-ATTAINMENT 

AREA, DOES NOT CONTRIBUTE SIGNIFICANTLY TO NONATTAINMENT OR INTERFERE WITH 

MAINTENANCE BY ANY OTHER STATE WITH RESPECT TO THE 0.08 PPM OZONE NAAQS. 

Regulation No. 7 Page 1 
IN A SEPARATE ACTION, THE COMMISSION HAS ADOPTED THE OZONE ATTAINMENT PLAN TO 

ADDRESS EPA's NON-ATTAINMENT DESIGNATION OF THE DMAINFR AREA. THE OZONE 

ATTAINMENT PLAN AND THE INTERSTATE TRANSPORT PLAN, TOGETHER, FORM THE BASIS FOR A 

CONCLUSION THAT COLORADO'S SIP SATISFIES CLEAN AIR ACT REQUIREMENTS PERTAINING TO 

GROUND-LEVEL OZONE. 

COLORADO AIR QUALITY CONTROL COMMISSION 

ADOPTED: DECEMBER XX, 2008 

Regulation No.7 Page 2 
Parties Hearing Documents
 

(this includes a list of the parties, the parties prehearing statements
 

and rebuttal statements, and any orders by the Commission)
 
Parties Hearing Documents 

PARTY 

- Air Quality Control Commission 

o Order to Deny Motion to Bifurcate
 

Air Pollution Control Division
 

o Motion to Bifurcate 

Anadarko Petroleum Company, Noble Energy, Inc., Whiting Oil and 

Gas Company, and Williams Production RMT Company 

o Response to Bifurcation
 

WildEarth Guardians
 

o Response to Bifurcation 
RECEIVE[j1 

BEFORE THE AIR QUALITY CONTROL COMMISSION NOV 28 2008 

STATE OF COLORADO 

A1RQUAUTY -----------------------------;oNT.u:::RQl:-::::=::COMt"ISS10 

ORDER 

TO DENY MOTION TO BIFURCATE - November 28,2008 

IN THE MATTER OF PROPOSED REVISIONS TO THE AMBIENT AIR QUALITY 

STANDARDS REGULATION, REGULATION NUMBERS 3,·7, AND 11 FOR THE 

DENVER METROPOLITAN & NORTH FRONT RANGE AREA OZONE ACTION 

PLAN. 

This matter came before the Hearing Officer on a motion ofthe Colorado 

Department of Public Health and Environment, Air Pollution Control Division 

("Division"), to bifurcate the proceeding and separately considerthe proposed Interstate 

Transport SIP revision. 

The public has received notice that the Interstate Transport SIP may be revised on 

a statewide basis to address the interstate transport of ozone as a part of the 

Commission's consideration of the proposed ozone action plan and accompanying 

proposed regulatory revisions. The public has had an opportunity to review the proposed 

revisions to the Interstate Transport SIP and provide comment regarding those revisions. 

After considering the motion and the responses, and having been otherwise fully 

informed, hereby orders that the motion to bifurcate the hearing be denied. 

It is also order by the Hearing Officer that: 

1.	 The Division will provide a revised Chapter V, Section H of the proposed Ozone 

Action Plan that is responsive to the comments of EPA to the extent that they 

remain within the scope of the noticed rulemaking hearing. The Division will 

provide this response to the Commission Office and the parties to the rulemaking 

hearing by 3:00 PM, Monday, December 1,2008. 

2.	 The Division response, along with the Motion to Bifurcate, the responses of the 

parties and this order shall be provided to the Commissioners as soon as 

practicable after its receipt. 

3.	 The parties to the hearing may provide a response to the Division's December 1, 

2008 filing. The parties will provide any responses to the Division's December I, 

2008 filing by 1:00 PM, Friday, December 5, 2008. The parties will provide their 

responses to the Commission office and to each other party to the rulemaking 

hearing and the Division. The Commission Office will provide the response of 

the parties to the Commissioners as soon as is practicable after their receipt. 
4.	 The Commission shall consider the interstate transport plan provisions of the 

proposed ozone action plan in the scheduled rulemaking hearing, but shall take a 

separate action in regard to the proposed interstate transport provisions at the 

conclusion of the rulemaking hearing for the proposed ozone action plan in 

response to the comments of EPA. 

So Ordered, this 28th day ofNovember 2008. 

Commissioner Barbara Roberts 

Hearing Officer 
RECEIVED 

BEFORE THE AIR QUALITY CONTROL COMMISSION WOV 13 2008 

STATE OF COLORADO AlRQUALID 

carontalIMISSlQI\' 

AIR POLLUTION CONTROL DIVISION'S MOTION TO BIFURCATE INTERSTATE 

TRANSPORT SIP REVISION 

IN THE MATTER OF PROPOSED REVISIONS TO THE AMBIENT AIR QUALITY 

STANDARDS REGULATION, REGULATION NUMBERS 3. 7, AND II FOR THE 

DENVER METROPOLITAN &NORTH FRONT RANGE AREA OZONE ACTION PLAN. 

The Colorado Department of Public Health and Environment, Air Pollution Control 

Division ("Division"), through the Office of the Attorney General, moves the Commission to 

bi furcate the hearing in this matter, and in support of this motion, offers the following: 

1.	 During the September 18th Request for Hearing on the proposed Ozone Action Plan, at 

the request of the Division, the Commission added Section H. "Section II O(a)2­

Transport Requirements," to Chapter V ofthe 8-hour Ozone State Implementation Plan, 

Photochemical Modeling and Other Weight ofEvidence Analyses For Attainment 

Demonstration. The Division proposed this section to address EPA as well as 

stakeholder comments concerning ozone transport and to ensure that the Ozone SIP has 

no deficiency concerning the Interstate Transport of ozone. 

2.	 Colorado is required to submit an Interstate Air Pollutant Transport SIP (Transport SIP) 

pursuant to the Clean Air Act, 42 U.S.c. Section 741 0(a)(2)(D)(i). 

3.	 The Commission adopted a Transport SIP in February of2007. That plan was submitted 

to EPA in Jtme of2008. 

4.	 EPA has provided preliminary comment to the Division indicating that the Transport SIP 

has deficiencies. EPA has also commented that the Transport SIP should be separated 

from the Ozone SIP because the plans are separate elements of the State Implementation 

Plan. 

5.	 Based on this comment, the Division proposes that the Commission bifurcate the 

proceeding, separate the Transport SIP from the Ozone SIP and consider Transport SfP in 

a separate hearing during the Commission's December meeting. The scope of noticed . 

revisions remains the same. The Transport SIP document is attached hereto. 

6.	 The public, including all parties to this proceeding, has received notice of a pending
 

proposal on the Transport SIP via the Notice of Hearing for the Ozone Action Plan,
 

which states:
 

The ozone action plan proposes to modify the provisions of the Interstate Air 

Pollutant Transport State Implementation Plan element adopted by the 

Commission in February 2007. by noting that the proposed maintenance plan 

would prevent the Colorado Front Range from contributing significantly to 

ozone non-attainment or interfere with (ong-term maintenance of the national 

ozone standard in any other state. 
7.	 The Notice of Hearing in this matter put the public on notice that the Commission would 

be considering modifications to the Transport SIP. If the notice and opportunity to 

comment are to have any meaning, changes to the original proposal must be reasonably 

expected. As long as any changes to the noticed proposal are a logical outgrowth of the 

original proposal, the changes comport with administrative procedure. Long Island Care 

at Home, Ltd. v. Coke, 127 S.Ct. 2339,2351 (U.S., 2007). 

Therefore, the Division respectfully requests that the hearing officer issue an order 

bifurcating this proceeding and schedule a separate hearing during the Commission's 

December meeting, and thereafter considering the attached revisions to the Transport SIP. 

DATED this 13th day of November 2008. 

JOHN W. SUTHERS 

Attorney General 

~-... =­ /.,	 . 

?" THOMAS A. ROAN, 30867* 

Assistant Attorney General 

Environmental Quality 

Natural Resources and Environment Section 

Attorneys for AIR POLLUTION CONTROL 

DIVISION 

1525 Shennan Street, 5th Floor 

Denver, Colorado 80203 

Telephone: (303) 866-5280 

*CounseI of Record 

2 
CERTIFICATE OF SERVICE 

I hereby certify on this 13th day of November, 2008, a true and correct copy of the 

foregoing Motion to Bifurcate Interstate Transport SIP Revision and CAA 110 (a)(2)(D)(i) 

Interstate Transport Draft was served on the following via electronic mail: 

Jeremy Nichols 

WildEarth Guardians 

1536 Wynkoop, Suite 302 

Denver, CO 80202 

jnichols(ffwiIdeanhguardi alls,org 

Michael E. Korenblat Jay Christopher 

Director, Legal Affairs Manager, Environmental 

Suncor Energy (U.S.A.) Inc. Suncor Energy (U.S.A.) Inc. 

7800 East Orchard Road, Suite 300 Denver West Refinery 

Greenwood Village, CO 801 I I 5801 Brighton Blvd. 

mkorenblat@suncor.com Commerce City, CO 80022 

jchristopher@sllllcor.com 

Allan L. Hale 

Amanda A. Bradley 

Matthew W. Spengler 

Hale Friesen, LLP 

1430 Wynkoop St., Suite 300 

Denver, CO 80202 

ahal e@halefriesell.colll 

abradley@.halcfricscn.com 

!11spenglerC{lihalefriesell. com 

Daniel J. Schnee 

El Paso Western Pipelines 

2 North Nevada, No. 1414 

Colorado Springs, CO 80903 

daniel.sclmec(aklpaso.colll 

Ted Orf 

Dianna L. Orf 

Orf & OrfPC 

1410 Grant St., Suite C-207 

P.O. Box 102036 

Denver, CO 80250-2036 

Jaw({i.~orfco.l1e[

(counsel for the Colorado Mining Association) 

Stan Dempsey, Jr. 

Colorado Petroleum Association 

1580 Lincoln St., Suite 1125 

Denver, CO 80203 
sran(2i.coloradopetrolclimassociatioll.org 

Jeffrey W. Schwarz
 

Carver Schwarz McNab & Bailey, LLC
 

1600 Stout St., Suite 1700
 

Denver, CO 80202
 

b-c Il\varz@..ck~m b.colll
 

(counsel for DCP Midstream, LP)
 

Linda L. Rockwood
 

Eric J. Triplett
 

Faegre & Benson, LLP
 

1700 Lincoln St.
 

3200 Wells Fargo Center
 

Denver, CO 80203
 

lrockwood@faegre.com
 

et ri pIett(a!rae gre.com
 

(counsel for Public Service Company of
 

Colorado (PSCo)
 

Steve Cook
 

Denver Regional Council ofGovemments
 

1290 Broadway, Suite 700
 

Denver, CO 80203
 

scook(chlrcog.org
 

Kevin Lynch
 

Environmental Defense Fund
 

Rocky Mountain Office
 

2334 North Broadway
 

Boulder, CO 80304
 

klvllch@edf.org
 

Kenneth A. Wonstolen 

Benjamin Vetter 

Fulbright & Jaworski LLP 

370 It h St., Suite 2150 

Denver, CO 80202 

k.!Vollsto len(U; fu Ibri l!ht.co1l1 

bvcttcncUu Ibn llht.com 

(counsel for the Colorado Oil & Gas Association) 

John R. Jacus 

Todd A. Weaver 

Abby J. Gaffney 

Davis Graham & Stubbs LLP 

1550 It h St., Suite 500 

Denver, CO 80202 

Lauren C. Buehler 

Xcel Energy, Inc. 

1225 Seventeenth St., Suite 900 

Denver, CO 80202 

Laurcn.C.Buehler(a!xcelenergy.com 

Meg Collins, President 

Colorado Oil & Gas Association 

1660 Lincoln St., Suite 2710 

Denver. CO 80264 

!1l9ll.COllins((licoga.org 
john.jacus@dgslaw.com 

todd.weaver((i;dgslavv'.com 

abby. ga rfney(ci,dgslaw.com 

(counsel for Anadarko Petroleum Corporation, 

Noble Energy, Inc., Whiting Oil and Gas 

Corporation, and Williams Production RMT 

Company) 

Colin G. Harris
 

Holme Roberts & Owen LLP
 

1801 13lh St., Suite 300
 

Boulder, CO 80302
 

colin.harris(c(hro.com
 

(counsel for EnCana Oil & Gas (USA) Inc.)
 

Pamela H. Milmoe
 

Air/Waste Program Coordinator
 

Boulder County Public Health
 

3450 Broadway
 

Boulder, CO 80304
 

pmilmoe@bouidercolillty.org
 

Richard L. Griffith
 

Richard L. Griffith, LLC
 

1580 Lincoln St., Suite 700
 

Denver, CO 80203
 

ricklgri f(a~~aol.com
 

(counsel for Colorado Ethanol Group)
 

Kenneth Lloyd 

Regional Air Quality Council 

1445 Market St., Suite 260 

Denver, CO 80202 

klloydui'faqc.org 

Suzette Mallette 

North Front Range Metropolitan Planning 

Organization 

419 Canyon 

Fort Collins, CO 80521 

smalktte(cLnfimpo .org 

Diane M. Blieszner 

EnCana Oil & Gas (USA) Inc. 

370 17th St., Suite 1700 

Denver, CO 80202 

dialle.blicsznen'(l~EnCana.co11l

Gregg Thomas 

Sabrina M. Williams 

Denver Environmental Health 

201 W. Colfax Ave., Dept. 1009 

Denver, CO 80202 

Gregg.thornas({udenvergov.org 

Sabrina.williams@denv~[gQv.org

(representing Local Government Coalition) 
Barbara Roberts, Commission Hearing Officer 

Ashley Campsie, Commissioner 

Rad Byerly, Commissioner 

Doug Lempke, Administrator 

Theresa Martin, Program Assistant 

Air Quality Control Commission 

4300 Cherry Creek Drive South 

EDO-AQCC-A5 

Denver, CO 80246 

barbarawrobgrts(Zi;comcasl.nct 

ashlev.campsie(a~eh2m.coln
 

hrbverl v~l;emai l.eom
 

90uglas.lcmpkca-vstate.co.LLs
 

theresa. marli n(custalc.eo.lIs
 

Kirsten King
 

Mike Silverstein
 

Air Pollution Control Division
 

4300 Cherry Creek Drive South
 

APCD Bl
 

Denver, CO 80246
 

kirsten.k ing(iL~'Slatc.co.lIs
 

mikc.si Ivcrstci n@:statc.co.us
 

Jerry Goad, Commission Attorney 

William Allison, Division Attorney 

Office ofthe Attorney General 

1525 Shennan St. 

Denver, CO 80203 

jerry.goad('(t:state.eo. us 

wi lliam.all iSOrl((ustale.co. us 

Kerri Fiedler 

US EPA Region 8 

1595 Wynkoop St. 

8P-AR 

Denver, CO 80202-1129 

II edlcr. kerri<iiepa.go\: 
ReCEIVED 

UEe 01 200B 

~jkOUAUTY
 

PROPOSAL TO REVISE COLORADO's INTERSTATE TRANSPORT IMPLEMENTATl~.r~:U):MlISSDi
 

PLAN FOR THE 1997 8-HOUR OZONE NAAQS
 

Overview: 

In September 2008, the Air Pollution Control Division (Division) included interstate ozone 

transport summary language and technical support information as part of the proposed Denver 

Metro AreaINorth Front Range 8-hour Ozone Action Plan. At that time, the Division found that 

Colorado air pollution sources do not contribute significantly to nonattainment of or interfere 

with maintenance with the 1997 8-hour ozone National Ambient Air Quality Standard of 0.08 

parts per million in another state. This finding is required by the Clean Air Act, Section 110 

(a)(2)(D)(I) regarding interstate transport. 

As a result of its review of the Ozone Action Plan, EPA noted that the Interstate Transport Plan 

does not belong in the Ozone Action Plan because of the Plan's limited focus on the Front Range 

region and not the entire State, as is required. The Division concurred with this finding and then 

asked the Commission to bifurcate the hearing so that the ozone element of the Interstate 

Transport Plan would be heard and considered separately. The Commission Pre-hearing officer 

has since determined that it is appropriate to hear the State-wide Ozone Interstate Transport Plan 

as part of the proposed Ozone Action Plan public hearing, but there would be a separate motion 

to approve the Transport Plan. 

The Division has removed the ozone transport summary language from the Ozone Action Plan 

and has created a stand-alone State-wide Ozone Interstate Transport Plan (attached). This standalone plan has been available to the public as part of the Ozone Action Plan's technical support 

document since November 6,2008. 

Background: 

In November 2006, the Air Quality Control Commission adopted an Interstate Transport Plan 

addressing both the 8-hour ozone NAAQS and for PM-2.5 NAAQS. This SIP document was 

transmitted to EPA following legislative review in June 2007. EPA has since provided informal 

comments on November 12,2008 (via email) identifying deficiencies in the ozone and PM-2.5 

Interstate Transport Plan. EPA's comments on the ozone portion of the Plan and the Division's 

response are as follows: 

I.	 EPA (pg. 1): Colorado must demonstrate that it will not contribute significantly to 

nonattainment or interfere with maintenance of the 8-hour ozone NAAQS. 

Division: The revised document for ozone makes an affirmative declaration that is
 

summarized in the conclusion of the document (Section 1.6).
 

2.	 EPA (pg 1): The 2007 Plan referred to Colorado's deferred nonattainment status and 

doesn't reference subsequent violations of the 8-hour ozone NAAQS (over a year after 

the hearing). EPA requests this section be rewritten. 

Division: The revised document does address the violations of the ozone NAAQS. 
3.	 EPA: The previous document used the Early Action Compact (EAC) modeling as a 

technical basis for conclud ing there are no interstate impacts. EPA requests this section 

be updated. 

Division: The revised document has been updated to include an analysis of results from 

the Ozone Action Plan base case modeling and recent monitoring data to conclude that 

Coloradowill not cause or significantly contribute to nonattainment in, or interfere with 

maintenance by, any other state with respect to the 0.08 ppm 8-hour ozone NAAQS.. 

4.	 EPA: EPA points out the dated language in the Plan about the EAC. They request that
 

this be updated.
 

Division: The revised document does remove all inconsistent language and out dated 

references to the EAC. 

5.	 EPA: EPA requests that the state specifically address why, with the exceedances
 

mentioned, Colorado does not contribute to nonattainment in other states.
 

Division: The revised document has been restructured to provides answers to this 

question in Section IA.2,Section 1.5, and in the Conclusion. 

6.	 EPA: EPA has requested that the State remove outdated language on the Clean Air
 

Interstate Rule (CAIR) modeling from the narrative.
 

Division: References to the CAIR modeling have been removed. 

7.	 EPA: EPA has requested the State remove language relating to "maintenance plans" and 

use the term, "maintenance". 

Division: References to "maintenance plans" have been removed from the revised 

document. The analysis and language in the revised document address "maintenance" as 

required by Clean Air Act, Section 110 (a)(2)(D)(I) regarding interstate transport. 

8.	 EPA: EPA has commented that the State should refer to the specific standard in question, 

in this case the 1997 8-hour NAAQS for ozone. 

Division: This has been addressed in the revised document. 

9.	 EPA has commented on the unclear graphs in the original report. 

Division: The graphs in the revised document have been fixed to be more readable. 

EPA's comments on the PM2.5 and visibility portions ofthe Plan are not addressed at this time 

and will be addressed at a later date. 
The Division requests that the Commission approve the State-wide Ozone Interstate Transport 

State Implementation Plan. 
Bi-frication 'motion to be denied 

Overview document from the Division: 

Description of what we've done 

Response to comments 

Remove text from OAP made a stand alone document 

Monday: Denial order goes out wi original bi-frication motion, two Party responses to the 

motion. And the Division's overview paper and the Plan 
State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)
 

Interstate Transport Regarding 8-Hour Ozone
 

DRAFT
 

November 5, 2008 

Colorado Department of Public Health and Environment 

Air Pollution Control Division 

4300 Cherry Creek Drive South 

Denver, Colorado 80246 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

i
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table of Contents 

I. OZONE-SPECIFIC PROVISIONS TO MEET THE REQUIREMENTS OF CAA 1I0(A)(2)(D)(I)­

INTERSTATE TRANSPORT 1 

1.1. INTRODUCTION I 

1.2. COLORADO OZONE MONITORING NETWORK 2 

1.3. OZONE MONITORING NETWORK IN NEARBY STATES 7 

104. OZONE TRANSPORT CONCLUSIONS FROM TIlE DMAINFR PHOTOCHEMICAL MODELING 10 

1.4.1. Emission Inventories and 2006 and 2010 Base Case _ 11 

1.4.2. Discussion 0/2010 Base Case CAMx Modeling Results 15 

1.5. DENVER METRO AREAINORTH FRONT RANGE OZONE NONAITAINMENT AREA CONTRIBUTION TO 

DOWNWIND LOCATIONS 18 

1.6. SECTION I IO(A)2 - OZONE TRANSPORT CONCLUSIONS 20 

2. REFERENCES 22 

List of Tables 

Table 1: 2008 I-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008) 4 

Table 2: 2008 8-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008) 5 

Table 3: Monitored 8-Hour Design Value Using the 3-Year (2006-2008) Average of the Fourth 

Maximum Ozone Concentration 6 

Table 4: 2005-2007 3-Year Fourth Highest Average Monitoring Concentrations from Kansas, 

Nebraska, New Mexico, Utah and Wyoming (see Table 5 for additional data) 7 

Table 5. 2005-2007 3-Year Fourth Highest Average Monitoring Concentrations from Kansas, 

Nebraska, New Mexico, Utah and Wyoming (see Table 4 for additional data) 8 

Table 6. Base Case Inventories for 8-Hour Ozone DMAlNFR NAA Photochemical Modeling 14 

List of Figures 

Figure 1. Location of Front Range Ozone Monitors 2 

Figure 2. Location of Statewide Ozone Monitors 3 

Figure 3: 8-Hour Ozone Nonattainment Areas 9 

Figure 4. Nested 12/4 km modeling domains for the Denver CAMx air quality and SMOKE 

emissions modeling 10 

Figure 5. Projected 2010 8-hour ozone Design Values (DVF) 15 

Figure 6. Rocky Flats North source apportionment for 29 July including boundary conditions 16 

Figure 7: Spatial extent ofthe 8-hour ozone concentrations that occurred between lOam and 6pm 

local time on June 27, 2002 through July 1, 2002 19 

ii 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(DXi) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

iii
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section ItO (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1. Ozone-Specific Provisions to Meet the Requirements of 

CAA 11 O(a)(2)(D)(i) - Interstate Transport 

1.1. Introduction 

The purpose of this document is to provide a technical basis for the State of Colorado's 

plan to meet the requirements ofthe Clean Air Act Section 110 (a)(2)(D)(i) Interstate 

Transport requirements regarding the 0.08 parts per million (ppm) 8-Hour Ozone National 

Ambient Air Quality Standard (NAAQS). This addresses the applicable components of 

110(a)(2)(D)(i) demonstrating adequate provisions to prevent emissions from Colorado 

from interfering with attainment or maintenance ofthe federal ozone NAAQS in any other 

state. This analysis does not address ozone transport for the revised 0.075 ppm 8-Hour 

Ozone NAAQS. 

This document replaces the section titled "Ozone-Specific Provisions" in the document 

"State of Colorado Implementation Plan to Meet the Requirements of Clean Air Act 

Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone and PM2.5 

NAAQS." 

Currently, the Denver area is the only area in U.S. Environmental Protection Agency 

(EPA) Region VIII that is designated as nonattainment for the 8-hour ozone NAAQS of 

0.08 ppm. 

In this report, relevant information from the Denver Metropolitan Area and North Front 

Range (DMA/NFR) 8-hour Ozone State Implementation Plan (SIP) process, the Denver 

Early Action Compact (EAC) process, ambient ozone data for Colorado, ambient ozone 

data for nearby states from the EPA Air Quality System (AQS) database, and other 

information is used to demonstrate that Colorado does not contribute significantly to 

nonattainment in, or interfere with maintenance by, any other state with respect to the 0.08 

ppm ozone NAAQS. 

1 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean- Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment I Air Pollution Control Division 

1.2. Colorado Ozone Monitoring Network 

The 2007/2008 ozone ambient air monitoring network in the Denver area and along the 

northern Front Range consists of 13 stations operated by the Colorado Air Pollution 

Control Division (APCD) and one station operated by the National Park Service (NPS) in 

Rocky Mountain National Park. There have been other stations that have operated in the 

past. The geographical distribution ofthe Front Range monitors is presented in Figure 1. 

As shown in Figure 1, the ozone monitors are primarily located in urbanized areas along 

the Front Range corridor. The monitors are located in areas where the highest ozone 

concentrations have been monitored historically and where elevated ozone is expected to 

occur. High ozone concentrations along the Front Range occur near the areas with high 

emissions density and dense population. In addition, elevated ozone is observed along 

elevated terrain to the west ofthe DMAlNFR Nonattainment Area. All ofthese monitors 

are designated by the U.S. Environmental Protection Agency as "equivalent" analyzers and 

follow all quality assurance requirements as specified in 40 CFR Part 58, Appendix A. 

Figure I. Location ofFront Range Ozone Monitors 

2
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment I Air Pollution Control Division 

Figure 2 shows other ozone monitoring sites that exist in Colorado for 2008. These are 

operated by either Colorado, the Southern Ute Tribe, or various Federal agencies. All of 

these sites use monitors that are designated as "equivalent" analyzers by the U.S. 

Environmental Protection Agency. As shown, most ofthe sites are in the southwest comer 

ofColorado, either within or near the San Juan oil and gas development area. 

Figure 2. Location of Statewide Ozone Monitors 

Table 1, Table 2, and Table 3 present the monitoring data for the DMAINFR NAA 

monitoring sites (including the NPS Rocky Mountain National Park monitoring site) as 

well as for other sites in Colorado. In Table 3, the fourth maximum 8-hour ozone 

concentrations along with the 3-year average ofthe fourth maximum concentrations at each 

site are presented. As shown in both Table I and Table 3, the Denver area is currently 

meeting the 8-hour and former I-hour ozone NAAQS for all sites, except for the 8-Hour 

NAAQS at Rocky Flats North with a design value of 0.86 ppm. 

3
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table I: 2008 I-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008) 

AQS 

Number Site Name 

1st Max 

I-Hour 

(ppm) 

Date 

1st Max 

I-Hour 

2nd Max 

I-Hour 

(ppm) 

Date 

2nd Max 

I-Hour 

3rd Max 

I-Hour 

(ppm) 

Date 

3rd Max 

I-Hour 

4th Max 

I-Hour 

(ppm) 

Date 

4th Max 

I-Hour 

08-001-3001 Welby 0.100 08/29 0.095 08/05 0.092 07/10 0.089 06/20 

08-005-0002 • Highland 0.065 04/04 0.064 04/08 0.064 04/18 0.062 04/19 

08-013-0011 S. Boulder Creek 0.089 07/10 0.089 07125 0.086 07/16 0.085 05/31 

08-031-0014 Carriage 0.094 08/05 0.090 08/29 0.089 07/10 0.085 06120 

08-031-0025 •• Denver - Animal 

Shelter 0.100 07/10 0.098 08/05 0.087 06/20 0.087 08/24 

08-035-0004 Chatfield State Park 0.101 07/10 0.098 06120 0.095 08129 0.092 08124 

08-041-0013 Colo. Spgs. ­

Academy 0.085 OS/24 0.083 07/10 0.082 08/06 0.080 07/18 

08-041-00.16 Manitou Springs 0.087 OS/24 0.085 08/06 0.083 07/10 0.083 07/11 

08-045-0012 •• Rifle - Health 0.081 07/09 0.080 07/10 0.075 08/19 0.074 07/11 

08-059-0002 Arvada 0.093 08/05 0.093 08/29 0.092 07/10 0.088 07/25 

08-059-0005 Welch 0.102 07/10 0.090 06/20 0.088 08/05 0.088 08/29 

08-059-0006 Rocky Flats - N 0.088 07/10 0.088 07/18 0.088 08129 0.087 07/02 

08-059-00 II NREL 0.097 08/29 0.093 07/10 0.092 08/05 0.092 08/24 

08-067-7001 ••• So. Ute'-

Ignacio 0.076 06/04 0.075 05/31 0.073 05/03 0.072 05/3 

08-067-7003 

••• So. UteBondad 0.080 06/04 0.078 05/31 0.077 OS/27 0.071 04/21 

08-067-???? USFS - Shamrock 0.081 06/04 0.079 06/10 0.077 02/29 0.077 05/30 

08-069-0007 Rocky Mountain 

Nat'l Park 0.092 07/09 0.090 07/31 0.090 08/28 0.085 OS/22 

08-069-00 II Ft. Collins - West 0.093 08/19 0.092 07/09 0.092 07/18 0.088 07/24 

08-069-1004 Ft. Collins - CSU 0.082 08/19 0.080 07/09 0.079 08/30 0.078 07/24 

08-077-0020 •• Palisade - Water 0.081 07/09 0.079 07/10 0.075 07/08 0.074 07/05 

08-083-0006 •• Cortez 0.078 07/23 0.074 07/13 0.072 08/05 0.071 07/25 

08-083 -0 I0 1 Mesa Verde Nat'l 

Park 0.075 05/01 0.075 06/04 0.074 05/31 0.072 04/30 

08-123-0009 Greeley - Weld 

Tower 0.094 08/20 0.092 07/24 0.089 08/01 0.087 08/04 

NOTES: 

• Highland site shut down on 4/21/08 for approx. 6-months.
 

•• Denver - Animal Shelter site commenced on 4/22/08, Rifle - Health commenced on 6/20/08,
 

Palisade - Water commenced on 5/30/08 and Cortez commenced on 6/17/08. 

••• Southern Ute sites data only thru 6/30/08. 

4
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(O)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table 2: 2008 8-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008) 

AQS 

Number Site Name 

1st Max 

8-Hour 

(ppm) 

Date 

Ist Max 

8-Hour 

2nd Max 

8-Hour 

(ppm) 

Date 

2nd Max 

8-Hour 

3rd Max 

8-Hour 

(ppm) 

Date 

3rd Max 

8-Hour 

4th Max 

8-Hour 

(ppm) 

Date 

4th Max 

8-Hour 

08-001-3001 Welby 0.085 07/10 0.083 08/29 0.077 01/18 0.076 06/20 

08-005-0002 * Highland 0.062 04/04 0.060 04/08 0.060 04/18 0.059 04/05 

08-013-0011 S. Boulder Creek 0.080 07/10 0.076 05/31 0.076 07/09 0.076 07/18 

08-031-0014 Carriage 0.081 07/10 0.075 08129 0.073 06/20 0.072 07126 

08-031-0025 ** Denver - Animal 

Shelter 0.086 07/10 0.072 08/29 0.071 07/13 0.070 07/26 

08-035-0004 Chatfield State Park 0.090 07/10 0.082 06/30 0.080 06/20 0.080 06127 

08-041-0013 Colo. Spgs. ­

Academy 0.078 OS/24 0.077 07/10 0.073 08/06 0.070 07/18 

08-041-0016 Manitou Springs 0.080 OS/24 0.076 07/10 0.074 07/11 0.072 07/31 

08-045-0012 ** Rifle - Health 0.076 07/09 0.076 07/10 0.069 08/19 0.066 071I3 

08-059-0002 Arvada 0.081 08/29 0.080 07/10 0.077 06/20 0.074 08/05 

08-059-0005 Welch 0.095 07/10 0.079 06/20 0.077 07/18 0.073 08/19 

08-059-0006 Rocky Flats - N 0.083 07/10 0.080 07/18 0.079 05/3 J 0.079 08/29 

08-059-00 II NREL 0.085 071I0 0.085 08/29 0.077 06120 0.076 06/02 

08-067-700 I *** So. UteIgnacio 0.069 06/04 0.067 06/10 0.066 05/10 0.066 06/13 

08-067-7003 *** So. UteBondad 0.073 06/04 0.067 OS/27 0.067 05/31 0.067 06/05 

08-067-???? USFS - Shamrock 0.074 06/04 0.073 06/10 0.071 06/13 0.069 05/30 

08-069-0007 Rocky Mountain 

Nat'l Park 0.081 07/09 0.077 OS/25 0.077 07/31 0.076 05/31 

08-069-00 II Ft. Collins - West 0.081 07/18 0.079 07/09 0.078 OS/25 0.076 07/24 

08-069-1004 Ft. Collins - CSU 0.070 OS/25 0.070 07/09 0.068 07/18 0.066 05/31 

08-077-0020 ** Palisade - Water 0.077 07/09 0.075 07/10 0.070 05/31 0.070 07/29 

08-083-0006 ** Cortez 0.067 08/02 0.066 07123 0.065 08/07 0.064 08/05 

08-083-0101 Mesa Verde Nat'l 

Park 0.071 06/04 0.070 04/30 0.069 04/21 0.069 06/10 

08-123-0009 Greeley - Weld 

Tower 0.077 07/24 0.076 08/20 0.075 07/26 0.073 08/01 

NOTES: 

* Highland site shut down on 4/21/08 for approx. 6-months.
 

** Denver - Animal Shelter site commenced on 4/22/08, Rifle - Health commenced on 6/20/08,
 

Palisade - Water commenced on 5/30/08 and Cortez commenced on 6/17/08. 

*** Southern Ute sites data only thru 6/30/08. 

5
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section J] 0 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table 3: Monitored 8-Hour Design Value Using the 3-Year (2006-2008) Average of the Fourth Maximum 

Ozone Concentration 

Site Name AQS# 

2006 

7 

Maximum 

8-Hour 

Average 

Value (ppm) 

2007 

7 

Maximum 

8-Hour 

Average 

Value (ppm) 

2008 

7 

Maximum 

8-Hour 

Average 

Value (ppm) 

Design Value 

(2006 ­ 2008) 

3-Year 

Average 

4th Maximum 

Value (ppm) 

Welby 08-001-3001 0.069 0.070 0.076 0.071 

* Highland 08-005-0002 0.081 0.075 0.059 0.071 

S. Boulder Creek 08-013-0011 0.082 0.085 0.076 0.081 

Carriage 08-031-0014 0.072 0.076 0.072 0.073 

** Denver - Animal 

Shelter 08-031-0025 --­ --­ 0.070 ---

Chatfield State Park 08-035-0004 0.086 0.082 0.080 0.082 

USAF Academy 08-041-0013 0.072 0.072 0.070 0.071 

Manitou Springs 08-041-0016 0.076 0.072 0.072 0.073 

** Rifle - Health 08-045-0012 --­ --­ 0.066 --­

Arvada 08-059-0002 0.082· 0.079 0.074 0.078 

Welch 08-059-0005 0.081 0.080 0.073 0.078 

Rocky Flats - North 08-059-0006 0.090 0.090 0.079 0.086 

NREL 08-059-0011 0.083 0.085 0.076 0.081 

*** So. Ute - Ignacio 08-067-7001 --­ --­ 0.066 --­

*** So. Ute - Bondad 08-067-7003 0.063 0.071 0.067 0~067

USFS - Shamrock 08-067-???? 0.074 0.069 0.069 0.070 

Rocky Mountain Nat'l 

Park 08-069-0007 0.076 0.078 0.076 0.076 

Fort Collins - West 08-069-0011 0.087 0.085 0.076 0.082 

Fort Collins - CSU 08-069-1004 0.078 0.069 0.066 0.071 

** Palisade - Water 08-077-0020 --­ --­ 0.070 --­

** Cortez 08-083-0006 --­ --­ 0.064 --­

. Mesa Verde Nat'l Park 08-083-0101 0.074 0.070 0.069 0.071 

Greeley - Weld Tower 08-123-0009 0.082 0.074 0.073 0.076 

NOTES: 

* Highland site shut down on 4/21/08 for approx. 6-months.
 

** Denver - Animal Shelter site commenced on 4/22/08, Rifle - Health commenced on 6/20/08,
 

Palisade - Water commenced on 5/30/08 and Cortez commenced on 6/17/08. 

*** Southern Ute sites data only thru 6/30/08. Ignacio data invalid for 0112005 to 08/2007. 

6 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.3. Ozone Monitoring Network in Nearby States 

Table 4 and Table 5 present 8-hour ozone monitoring data from the surrounding states of 

Nebraska, Kansas, New Mexico, Wyoming, and Utah. Table 4 and Table 5 show that none 

ofthe monitors in surrounding states exceed the 8-hour ozone standard. Therefore, to the 

extent that the network is representative of all areas, it can be concluded that the 

DMA/NFR sources do not significantly contribute to the 8-hour ozone standard violations 

at these down wind locations or even further downwind. 

Table 4: 2005-2007 3-Year Fourth Highest Average Monitoring Concentrations from Kansas, Nebraska, 

New Mexico, Utah and Wyoming (see Table 5 for additional data) 

Site ID State County 

EPA 

Re2ion 

2005 

8-hr 

Ozone 

4th Max 

(ppm) 

2006 

8-hr 

Ozone 

4th Max 

(ppm) 

2007 

8-hr Ozone 

4th Max 

(ppm) 

3-yr 

Avg. of 

4th Max 

(ppm) 

20-045-0004 KS Douf:das 7 0.073 0.081 End 2007 N/A 

20-091-00 I0 KS Johnson 7 0.081 0.076 0.071 0.076 

20-103-0003 KS Leavenworth 7 0.077 0.074 0.080 0.077 

20-107-0002 KS Linn 7 0.075 0.079 0.070 0.074 

20-173-000 I KS Sedgwick 7 0.065 0.065 0.059 0.063 

20-173-0010 KS Sedgwick 7 0.074 0.073 0.060 0.069 

20-191-0002 KS Sumner 7 0.078 0.080 0.070 0.076 

20-195-0001 KS Trego 7 0.071 0.076 0.068 0.071 

20-209-0021 KS Wyandotte 7 0.079 0.081 0.073 0.077 

31-055-0028 NE Douglas 7 0.069 0.072 0.066 0.069 

31-055-0032 NE Douglas 7 0.067 0.066 0.056 0.063 

31-055-0035 NE Douglas 7 0.070 0.067 0.061 0.066 

31-109-0016 NE Lancaster 7 0.056 0.056 0.054 0.055 

35-001-0019 NM Bernalillo 6 0.073 0.073 0.070 0.072 

35-001-0023 NM Bernalillo 6 0.072 0.073 0.069 0.071 

35-001-0024 NM Bernalillo 6 0.074 0.074 0.068 0.072 

35-001-0027 NM Bernalillo 6 0.073 0.072 0.071 0.072 

35-001-0029 NM Bernalillo 6 0.071 0.070 0.067 0.069 

35-001-1012 NM Bernalillo 6 0.077 0.047 0.074 0.066 

35-001-1013 NM Bernalillo 6 0.077 0.071 0.071 0.073 

35-001-1014 NM Bernalillo 6 0.072 0.072 0.064 0.069 

35-013-0008 NM Dona Ana 6 0.070 0.072 0.068 0.070 

35-013-0017 NM Dona Ana 6 0.070 0.073 0.070 0.071 

35-013-0020 NM Dona Ana 6 0.072 0.072 0.068 0.070 

35-013-0021 NM Dona Ana 6 0.076 0.080 0.076 0.077 

35-013-0022 NM Dona Ana 6 0.070 0.073 0.073 0.072 

35-013-0023 NM Dona Ana 6 0.066 0.070 0.062 0.066 

7
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment I Air Pollution Control Division 

Table 5.2005-20073-Year Fourth Highest Average Monitoring Concentrations from Kansas, Nebraska, 

New Mexico, Utah and Wyoming (see Table 4 for additional data) 

Site ID State County 

EPA 

Resdon 

2005 

8-hr 

Ozone 

4th Max 

(ppm) 

2006 

8-hr 

Ozone 

4th Max 

(ppm) 

2007 

8-hr Ozone 

4th Max 

(ppm) 

3-yr 

Avg. of 

4th Max 

(ppm) 

35-015-1005 NM Eddy 6 0.067 0.076 0.066 0.069 

35-017-1003 NM Grant 6 0.071 0.067 0.062 0.066 

35-025-0008 NM Lea 6 0.074 0.075 0.064 0.071 

35-029-0003 NM Luna 6 Start 2006 0.053 0.062 N/A 

35-043-100 I NM Sandoval 6 0.069 0.064 0.063 0.065 

35-043-1003 NM Sandoval 6 0.075 0.074 0.071 0.073 

35-043-9004 NM Sandoval 6 0.076 0.072 0.067 0.071 

35-045-0009 NM San Juan 6 0.075 0.063 0.069 0.069 

35-045-0018 NM San Juan 6 Start 2006 0.079 0.079 N/A 

35-045-1005 NM San Juan 6 0.072 0.071 0.073 0.072 

49-003-0003 UT Box Elder 8 0.079 0.078 0.077 0.078 

49-003-700 I UT Box Elder 8 0.075 0.076 0.078 0.076 

49-005-0004 UT Cache 8 0.069 0.073 0.074 0.072 

49-0 11-0004 UT Davis 8 0.092 0.082 0.082 0.085 

49-035-0003 UT Salt Lake 8 0.083 0.084 0.082 0.083 

49-035-2004 UT Salt Lake 8 0.086 0.082 0.082 0.083 

49-035-3006 UT Salt Lake 8 0.082 0.082 0.079 0.081 

49-035-3007 UT Salt Lake 8 0.085 0.080 0.080 0.081 

49-035-3008 UT Salt Lake 8 0.080 0.082 0.079 0.080 

49-037-0101 UT San Juan 8 0.069 0.070 0.072 0.070 

49-045-0003 UT Tooele 8 0.080 0.079 0.076 0.078 

49-049-0002 UT Utah 8 0.078 0.074 0.075 0.075 

49-049-5008 UT Utah 8 0.080 0.077 0.078 0.078 

49-049-5010 UT Utah 8 0.080 0.079 0.077 0.078 

49-053-0130 UT Washington 8 0.091 0.072 0.071 0.078 

49-057-0007 UT Weber 8 0.081 0.083 0.080 0.081 

49-057-1003 UT Weber 8 0.084 0.083 0.082 0.083 

56-005-0123 WY Campbell 8 0.063 0.072 0.072 0.069 

56-005-0456 WY Campbell 8 0.063 0.065 0.072 0.066 

56-035-0098 WY Sublette 8 0.075 0.069 0.068 0.070 

56-035-0099 WY Sublette 8 0.079 0.072 0.067 0.072 

56-035-0100 WY Sublette 8 0.066 0.074 0.066 0.068 

56-037-0200 WY Sweetwater 8 Start 2006 0.067 0.064 N/A 

56-039-1011 WY Teton 8 0.060 0.069 0.065 0.064 

Figure 3 presents a map of all the U.S. nonattainment areas. Since the surrounding states 

of Kansas, Nebraska, Wyoming, Utah, and New Mexico do not have violations the 8-hour 

NAAQS for ozone, it can be reasonably concluded that Colorado sources do not 

significantly affect the ozone nonattainment areas even further downwind such as Dallas8
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(O)(i) -Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department ofPublic Health and Environment / Air Pollution Control Division 

Forth Worth and St. Louis nonattainment areas. In addition, it is unlikely that Colorado 

would significantly affect nonattainment areas that are typically "upwind" such as Las 

Vegas and Phoenix. However, it is recognized that, under the types of synoptic scale 

meteorological regimes that occur during some regional ozone episodes, simple terms like 

"upwind" and "downwind" may not be applicable. Thus, photochemical modeling is 

needed to study the distribution of ozone under a variety of meteorological regimes. 

Nonattainment and Maintenance Areas in the U. S. 

8-hour Ozone Standard 

Figure 3: 8-Hour Ozone Nonattainment Areas 

9
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
---

-120 

-240 

Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.4.	 Ozone Transport Conclusions from the DMA/NFR 

Photochemical Modeling 

The DMAlNFR photochemical model domain was defined on a nested 36-kilometer (km), 

12 km, and a 4 km nested-grid structure. This structure was utilized in conjunction with 

the Comprehensive Air-quality Model with extensions (CAMx) air quality model 

(ENVIRON, 2008). CAMx, SMOKE (Coats, 1996), and CONCEPT MS (Loomis et aI., 

2005) air quality and emissions modeling was performed for the June-July 2006 period. 

Nested 36/12/4 km modeling domains were used in the Denver 8-hour ozone modeling 

study. The CAMxmodel was first applied to the 36 km continental U.S. domain using 

boundary conditions (BCs) from a global climate air quality model. The CAMx 2006 and 

2010 base case modeling results from the 36 km continental U.S. domain simulation were 

then processed to generate BCs for the CAMx 12/4 km domain (Figure 4) for the 2006 12/4 

km base case and 2010 12/4 km base case and sensitivity simulations. The CAMx 

simulations for the 12/4 km domains were run using two-way interactive grid nesting (i.e., 

pollutants can flow back and forth between the 12 km and 4 km domains to account for 

recirculation). The larger 36km domain was selected to address the impact of boundary 

condition uncertainties for the Front Range area ofColorado, as APCD was concerned 

there may be transport from Southern California and Texas. The 12 km grid resolution 

domain essentially covers the central Rocky Mountain States or portions thereof (i.e., 

Arizona, Colorado, New Mexico, Utah and Wyoming.) The 4 km nested-grid covers most 

of the state ofColorado. 

480 

360 --I I 

240 I L 

r-i 

!----t:=__~;;;C;;AM~X~4k~1m:=!lI ._J 

I 

I 

120

0

I
 

I

I

\L
 

I

\1 I 

I
 I 

~_.
 

i-I	 \-\
 I

I . / CAMx 12k' 

> j 

-1680-1560-1440-1320-1200-1080 -960 -840 -720 -600 -480 -360 -240 -120 0 120 240 

I 

J' 

Figure 4. Nested 12/4 km modeling domains for the Denver CAMx air quality and SMOKE emissions 

modeling. 

10 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 

-360 

-480 

-600 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.4.1. Emission Inventories and 2006 and 2010 Base Case 

The photochemical modeling for the "2010 base case" emissions scenario perfonned for 

the DMAlNFR Ozone SIP process demonstrates compliance in the Front Range Region 

with the 8-hour 0.08 ppm ozone NAAQS. Control measures in place in 2006 and assumed 

for 2010 include: 

1.	 Federal tailpipe standards and regulations, including those for small engines and 

non-road mobile sources. Credit is taken for these federal requirements but they are 

not part of the Colorado SIP. The credits change from 2006 to 2010 as the United 

States Environmental Protection Agency (EPA) Tier II and low sulfur gasoline 

standards become effective. 

2.	 Air Quality Control Commission Regulation No. 11--covering the Automobile 

Inspection and Readjustment (A.I.R.) program in place during the 2006 ozone 

season, which includes an enhanced Inspection/Maintenance (11M). For 2006, a 

maximum of 10% fleet coverage is assumed, and for 2010, a maximum of 50% 

fleet coverage is assumed for the remote sensing clean screen program in the 

Denver metro area (DMA) based on Regulation No. 11. 

3.	 Air Quality Control Commission Regulations No.3, No.6, No.7, and Common 

Provisions--covering gasoline station and industrial source control programs. The 

Common Provisions, Parts A and B ofRegulation No.3, and the volatile organic 

compounds (VOC) control requirements of Regulation No.7 are already included 

in the approved SIP. Regulation No.6 and Part C of Regulation No.3 implement 

the federal standards of perfonnance for new stationary sources and the federal 

operating pennit program. This reference to Regulation No.6 and Part C of 

Regulation No.3 shall not be construed to mean that these regulations are included 

in the SIP. 

4.	 Since 2004, gasoline sold in the Denver metro area during the summer Reid Vapor 

Pressure (RVP) ozone season (June 1 to September 15) has been subject to a 

national RVP limit of 7.8 pounds per square inch (psi) to reduce fuel volatility. For 

ethanol-blended fuels, the RVP limit is 8.8 psi due to the federal 1.0 psi RVP 

waiver for ethanol. 

Since 1991, gasoline sold in the Larimer and Weld area during the summer ozone 

season (June 1 to September 15) has been subject to a national RVP limit of 9.0 psi 

to reduce fuel volatility. For ethanol-blended fuels, the RVP limit is 10.0 psi due to 

the federal 1.0 psi RVP waiver for ethanol. 

For 2006, the RVP of gasoline for the Denver metropolitan portion of 

nonattainment area was detennined by survey to be at 8.2 psi, with an ethanol 

market share of 60%, and for the Larimer and Weld portion of the nonattainment 

area the RVP was detennined to be 8.4 psi with the same ethanol share of 60%. For 

purposes of the base case 2010 mobile source inventory, the RVP of the base 

I1 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment I Air Pollution Control Division 

gasoline is assumed to be 7.8 psi for the Denver metropolitan portion of 

nonattainment area, with an ethanol market share of 85%, and for the Larimer and 

Weld portion of the nonattainment area the RVP was assumed to be 9.0 psi with an 

ethanol share of25%. 

5~	 The EPA approved the EAC Ozone Action Plan (OAP) on August 19,2005. The 

OAP included an amendment to Regulation No.7 requiring the reduction of flash 

emissions of volatile organic compounds from condensate collection, storage, 

processing and handling operations by May 1,2005. This initial rule required the 

installation of air pollution control technology to achieve a system-wide 47.5% 

reduction from uncontrolled emissions of volatile organic compounds from new and 

existing oil and gas exploration and production operations located within the 8-hour 

ozone nonattainment area designated by EPA for operators with total emissions 

greater than 30 tons per year. The 2006 base case estimate was developed from 

actual reported emissions based on the system-wide 47.5% reduction requirement. 

6.	 In February 13,2008, the EPA approved revisions to Regulation No.7 to require 

the system-wide reduction of condensate tank flash VOC emissions of 75% for the 

2007 ozone season by May 1, 2007 and 78% reduction for the 2012 ozone season, 

with technology that achieves a 95% reduction in VOC emissions. The 2010 base 

case emissions estimate assumes the 75% system-wide reduction requirement. 

7.	 The effect of EPA final locomotive Tier 3 standards were considered and included, 

where appropriate, in the 2010 area source estimates. Tier 4 locomotive standards 

do not go into effect until 2015 and therefore were not included in the 2010 

inventories. 

All ofthe inventories in this 8-hour Ozone Attainment SIP were developed using EPA 

approved emissions modeling methods, including EPA's MOBILE6 model and local VMT 

data for on-road mobile source emissions, EPA's non-road model and local demographic 

information for area and off-road sources, and reported actual emissions for point sources. 

Estimates for future emissions are based on the above-mentioned tools and the EPA's 

Economic Growth and Analysis System (EGAS) model for estimating future point sources 

activity, VMT growth for on-road mobile sources, and 2010 and 2012 demographic data 

for off-road and area sources. The technical support document contains detailed 

information on model assumptions and parameters for each source category. 

Highway mobile source emissions are from the ENVIRON Consolidated Community 

Emissions Processing Tool (CONCEPT) model inventory, which is based on DRCOG 

VMT data and MOBILE6 input data provided by APCD and expanded to the entire NAA 

based on VMT from the North Front Range Transportation and Air Quality Planning 

Council and CDaT. 

Non-road source emissions are from the EPA Non-Road Model. This model includes the 

impact of future controls on non-road engines, which is used in equipment such as lawn 

and garden equipment and construction equipment. Oil and gas source emissions are from 

12
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

the revised Independent Petroleum Association ofMountain States (IPAMS) inventory, 

and were projected to 20 lOusing the methodology in the IPAMS projection methodology 

document. The IPAMS inventory was sponsored by the IPAMS and is Phase III of a 

regional oil and gas emission inventory for the Inter-Mountain West jointly with the 

Western Regional Air Partnership (WRAP). 

Non-oil and gas area source emissions (including heating, consumer solvent use, aircraft 

and railroads, etc.) are from the 2002 EPA National Emissions Inventory (NEI), grown to 

2006 and 2010 by population growth from data from the State Demographer. Consumer 

solvent emission reductions based on 75% of the per-person reductions listed in the EPA 

May 30, 2007 Emission Reduction Credit Memo were applied to the projected 20 I0 nonoil and gas area source inventory. A check on the non-oil and gas area sources estimates 

comparing the recently available 2005 NEI emissions data is shown later in this document. 

An inventory completed in 2005 for Denver International Airport (DIA) was used for 

aircraft and airport non-road source emissions from DIA for both 2006 and 2010. 

Non-oil and gas point source emissions were grown to 2010 by the EPA EGAS economic 

model, and by adding sources for which permits have been issued. 

Emissions ofVOC and nitrogen oxides (NOx) from biogenic sources have been generated 

by the Model of Emissions ofGases and Aerosols from Nature (MEGAN) Biogenic 

Emissions Model using land cover data base of biomass type and density and hourly 

meteorology data. The National Center of Atmospheric Research (NCAR) has produced a 

global data base of land use data, the MEGAN Driving Variable Database Version 1.2, for 

use with MEGAN. Surface temperatures are provided by the Mesoscale Meteorological 

Model (MM5) modeling. 

Summaries of the VOC and NOx base case inventories for the nonattainment area for 2006 

and 2010 are presented in Table 6. Emissions ofNOx and VOCs are in tons per average 

episode day. Additional detail on the categories of emissions can be found in the TSD. 

Wildfire emissions, though not included in tables, have been considered for the background 

ozone concentrations in the modeling effort. Wildfire emissions can vary significantly on a 

day-to-day basis depending on conditions. 

13 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table 6. Base Case Inventories for 8-Hour Ozone DMA/NFR NAA Photochemical Modeling 

(tons per average episode day) 

2006 2010 

SOurce Category NOx: voc . NOx: VOC 

Point SOurces · Electric Generation Units (EGU) 55.6 : 0.7 58.5 : 1.6 

External Combustion Boilers 9.5 1 0.4 10.0 ; 0.5 

Industrial Processes 12.5 : 10.2 14.0; 11.0 

Petroleum and Solvent Evaporation 

Other 

0.3 ; 19.0 

3.1 ! 1.8 

0.3 : 22.0 

3.6 1 2.0 

Point Sources Subtotal 81.0 : 32.1 ,

, 

: 

, 126.5 

22.61 6.8 , 24.8 

16.2 

17.1 10.8 

39.7 185.2 

86.4 : 37.0 

·· · 

129.6 

23.6 8.6 

31.1 

20.4 

22.5 13.7 

46.2: 203.3 

Oil & Gas Point & Area Sources 

Condensate Tanks 

Other O&G Point Sources 

Pneumatic Devices (Area Source) 

Unpermitted Fugitives (Area Source) 

Other Area Sources 

O&G Point & Area Sources Subtotal 

Area Sources 

Personal Care Products 7.1 7.0 

Household Products 21.4 17.9 

Automotive Aftermarket Products 11.9 13.0 

Architectural Coatings 20.1 16.8 

Aircraft 7.4 1.3 8.2 1.5 

Railroad 12.8 0.5 13.8 0.6 

Other CoatingslPesticides/Cooking/ Miscellaneous. 3.9 4.1 

Area Source Subtotal 20.2 66.3 22.1 61.0 

Non-Road Mobile SOurces 

Agricultural Equipment 7.0 0.9 6.3 0.7 

Airport EqUipment 0.7 0.1 0.6 0.1 

Commercial Equipment 5.3 6.2 5.1 7.0 

Construction and Mining EqUipment 35.7· 5.5 31.2 4.5 

Industrial Equipment 10.5 2.4 6.9 1.4 

Lawn and Garden Equipment (Commercial) 9.4 359 8.9 28.1 

Lawn and Garden Equipment (Residential) 1.2 7.5 1.2 11.8 

Boats/Recreational Equipment/Miscellaneous 0.7 6.9 0.8 7.8 

Non-Road Mobile SOurce Subtotal 70.5 65.3 

165.5 129.7 

165.5 129.7 

376.8. 478.6 

63.0 : 694.0 . 429.8 : 1172.6 

61.0 61.3 

122.9 109.2 

122.9 109.2 

338.5 471.8 

53.0 694.0 

391.5 1165.8 

On-Road Mobile Sources 

On-Road Mobile (including vehicle refueling) 

On-Road Mobile Subtotal 

Anthropogenic Total 

Biogenic Total 

AnthroPOaenic & Bioaenic Total 

14 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.4.2. Discussion of2010 Base Case CAMx Modeling Results 

Currently, Colorado's highest emissions density is along the Front Range. As shown in 

Figure 5 Photochemical Modeling done for the DMA/NFR SIP process shows that the 

highest 2010 ozone design values along the foothills west of Denver and Fort Collins. 

Ozone concentrations decrease rapidly to the east of Denver. The maximum projected 2010 

base case 8-hour ozone Design Value of 84 ppb occurs at both the Rocky Flats North and 

Fort Collins West monitoring sites. As this value is 84 ppb or lower, the 2010 base case 

modeling results pass the EPA modeled attainment demonstration test. Although the EPA 

8-hour ozone projection procedure is to truncate the final projected DVF for comparisons 

with the NAAQS, the projected 2010 base case future years design value is 84.9 ppb 

(Morris, et ai, 2008a). 

~g~~/--L-;-L--JLeg.ld * Oz~ne Mondor 

o o>::u1ty'_ICP

J 0 51 .",_1", r------L O.m&f04km_dom_DV 

i r~--",.J-l BASE OW 

_ fj$ l1(1'" = jI( c.:= 6'5 00 

_ 65 :)0-< 'l'i' <,;; 1() (I (I 

70ilO<~<=r500

IS 1)0< 1. <='0000 

···lJI r

I 

··~·-T-----,---l----­ I 

t-----_I I 

/' 

,:~I.--r--'­

Figure 5. Projected 2010 8-hour ozone Design Values (DVF) 

Figure 6 presents the ozone source apportionment results, including the boundary 

conditions. The boundary conditions (BCs) show the contribution from sources outside the 

12 km domain (see Figure 4) for a given high ozone day (results vary by day). On this day, 

15
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

of the 76.1 ppb of ozone estimated at the monitor, approximately 48 ppb was transported 

into the 12 kIn domain and approximately 8 ppb was attributed to sources in the sevencounty Denver Metro area (Morris, et aI, 2008a) while the rest was from other counties in 

Colorado or from other states. This suggests that, on this day, ozone was generated 

primarily by globaVcontinental scale "background" and local sources of emissions in the 

Denver Metro area. Transport from nearby states was relatively small. 

run16c.osaUy20 10.1204
 

060729 (2006210)
 

Metric-03M Average >= 70.0 PPB
 

Total Ozone 76. 1 (pp b) - Receptor rfno
 

72 

64 

56 

48 

40 

32 

24 

Ie 

• Be • EGU 

• NonEGU 

• Area 

• OilGas 

• Nonroad 

• Motor Veh. 

• BioFire 

16 

8 

o 

t3 o o 0 + + C) 

u

w III Z ~ ~

GSAT Source Regi~s

Figure 6. Rocky Flats North source apportionment for 29 July including boundary conditions. 

Conclusions from ozone source apportionment results (Morris, et aI, 2008a) vary by day 

and by location. However, several overall trends emerged, namely: 

• Regional ozone transport into the 12 kIn domain is the largest contributor, often 

accounting for more than two-thirds of the total ozone; 

• At the Denver Metropolitan monitors the largest contributors are Denver 

Metropolitan metro area motor vehicle and non-road sources; 

• At the Fort Collins and Greeley monitors, the largest contributors tend to be 

Larimer and Weld County motor vehicles, non-road sources and oil and gas 

sources, and Denver Metropolitan sources; 

• The majority of the ozone fonned is attributable to anthropogenic NOx emissions. 

16
 

DRAFT - State ofColorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(DXi) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

In interpreting these results, it is important to keep in mind that the source apportionment 

results are based on the Denver SIP 2006 modeling episode and are meteorologically 

dependent For instance, the source apportionment modeling in support ofthe Denver 

Early Action Compact using a 2002 ozone episode (Morris, et aI, 2004a) showed more 

impact from sources in northern Colorado in the Denver Metropolitan area. 

Other ozone transport studies also confirm that Denver is impacted by ozone from areas 

well outside ofColorado. A report sponsored by the Western States Air Resources Council 

(WESTAR) indicates that, when ozone is greater than 85 ppb in Denver, natural 

background accounts for 37.5% of the total concentration, transported anthropogenic 

generated ozone is 37.5%, and the local anthropogenic ozone contribution is about 25% 

(MacDonald, et. aI, 2006). 

A common theme at all ozone monitors is that a majority of the peak 8-hour ozone is due to 

ozone transport from sources outside of Colorado and outside the 12km domain boundary. 

Source apportionment modeling indicates that transport into the region accounts for 

approximately 60-75% ofthe ozone formation in the DMA/NFR. This indicates that the 

DMA/NFR is more of a receptor ofozone and ozone precursors rather than a producer of 

ozone and precursors that transports ozone to areas outside of the Front Range. While the 

modeling suggests that the transport of ozone and/or ozone precursors is a significant issue 

in the west, the magnitude of ozone transport from Colorado to other states is too low to 

significantly contribute to nonattainment in, or interfere with maintenance by, any other 

state with respect to the 0.08 ppm ozone NAAQS. 

17
 

DRAFT - State ofColorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(DXi) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.5.	 Denver Metro Area/North Front Range Ozone Nonattainment 

Area Contribution to Downwind Locations 

As part of the Denver EAC, source apportionment modeling was conducted to evaluate the 

spatial extent of the 8-hour ozone impacts due to emissions from various source regions in 

Colorado. A similar analysis was not done as part of the DMA/NFR ozone SIP analysis, 

however, a similar conclusion would be expected. The conclusion is that ozone formed 

specifically from sources in the DMA/NFR nonattainment area decreases rapidly in 

concentration over the eastern plains of Colorado. Therefore, the photochemical modeling 

that was done for both the DMA/NFR ozone SIP and the Denver EAC suggest that ozone 

and/or ozone precursors from the Front Range do not contribute significantly to downwind 

monitors in other states. 

Figure 7 displays the spatial extent ofthe 8-hour ozone concentrations that occurred
 

between lOam and 6pm local time (the time when the daily maximum 8-hour ozone
 

typically occur) on June 27, 2002 through July 1,2002 due to all emissions (anthropogenic 

and biogenic) from the DMA. As shown in Figure 7, which represents a high ozone 

episode in Denver, the DMA can contribute approximately 10 ppb of ozone at the eastern 

border ofColorado. However, the concentration gradient falls offquickly and emissions 

from the DMA are not expected to be a significant contributor to any ozone nonattainment 

area downwind of the Front Range. Weld, Elbert, Morgan, Larimer, EI Paso and other 

counties contribute even less ozone to the Colorado border states with a maximum 

contribution of 5-10 ppb. 

18
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(DXi) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

S.OlIII 

•.000 

1'1'8 

Contributions to 3-hr Ozone 

fr_~~Al'.. CAMo< votM Zlib1<"""'''''~

I ",,;l..=._..1 

1 II 

Contributions to 3-hr OzonE' 

ConI I1bulion, to 8-hl" Oronp 

..... 

n"" 

Contributions to 8·llr Ozone 

Contribution., to 8-hr ()zon(' 

Figure 7: Spatial extent of the 8-hour ozone concentrations that occurred between lOam and 6pm local time 

on June 27, 2002 through July 1,2002 

19
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (aX2)(DXi) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment I Air Pollution Control Division 

1.6. Section 11 0(a)2 - Ozone Transport Conclusions 

With respect to the 0.08 ppm ozone NAAQS, emission control programs in the Colorado 

SIP are expected to adequately protect neighboring states from interstate transport of 

ozone, per Clean Air Act (CAA) Section 11O(a)(2)(D)(i). 

Ambient monitoring data in and around Colorado support the assertion that Colorado does 

not contribute significantly to nonattainment in, or interfere with maintenance by, any other 

state with respect to the 0.08 ppm ozone NAAQS. Specifically: 

1.	 A review of recent ozone observations from the EPA AQS database shows that, 

with the exception of a single monitor in Jefferson County, Colorado (Le., Rocky 

Flats North), all monitoring sites in Colorado and adjacent states that are likely to 

be impacted by Colorado demonstrated attainment of the 0.08 ppm 8-hour ozone 

NAAQS for the three year period of 2005-2007. Since ozone monitors in adjacent 

states comply with the 0.08 ppm NAAQS, it logically follows that Colorado does 

not cause or contribute to monitored violations or interfere with maintenance of the 

0.08 ppm ozone NAAQS in any other state. 

2.	 For Rocky Flats North, which is the only monitor in Colorado that has levels above 

the 0.08 ppm ozone NAAQS, the preliminary three-year average (2006-2008) 

fourth high value is 0.086 parts per million (ppm), which is only slightly above the 

0.08 ppm ozone NAAQS. 

3.	 Observations from current networks show that the highest ozone levels in Colorado 

occur along the Colorado Front Range and not in other areas of Colorado. 

4.	 Ozone monitoring data from the surrounding states that are most likely to be 

impacted by Colorado (i.e., Nebraska, Kansas, New Mexico, Wyoming, and Utah) 

show that none of the monitors exceed the 0.08 ppm 8-hour ozone standard. Since 

the areas represented by these monitors are in monitored attainment, it is highly 

unlikely that existing 0.08 ppm ozone nonattainment areas beyond these areas are 

significantly affected by emissions from Colorado. The nearest 0.08 ppm ozone 

nonattainment areas to DMA/NFR Nonattainment Area are: 

a.	 Phoenix, Arizona (Basic Area for 8-Hour ozone) at a distance of 586 miles; 

b.	 Las Vegas, Nevada (Basic Area for 8-hour ozone) at a distance of 628 

miles; 

c.	 Dallas, Texas (Moderate 8-hour ozone nonattainment area) at a distance of 

663 miles; and 

d.	 S1. Louis, Missouri (Moderate 8-hour ozone nonattainment area) at a 

distance of 796 miles. 

Photochemical modeling and other technical analyses performed for the Denver Early 

Action Compact (EAC) and the Denver Metro Area and North Front Range (DMA/NFR) 

8-hour Ozone SIP support the assertion that Colorado does not contribute significantly to 

20 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(DXi) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

nonattainment in, or interfere with maintenance by, any other state with respect to the 0.08 

ppm ozone NAAQS. Specifically: 

I.	 The Denver 8-hour Ozone SIP photochemical modeling for 20 I0 and the associated 

weight of evidence analyses suggest that the DMAlNFR nonattainment area and 

downwind areas already comply or will comply with the 0.08 ppm ozone NAAQS 

by 2010. 

2.	 Photochemical modeling shows that elevated ozone concentration levels generated 

from local emissions decrease rapidly with distance. 

3.	 A review of photochemical modeling perfonned for both the DMA/NFR Ozone SIP 

and the Denver EAC, including boundary condition analyses, suggests that the 

magnitude of ozone transport from Colorado to other states is too low to 

significantly contribute to nonattainment in, or interfere with maintenance by, any 

other state with respect to the 0.08 ppm ozone NAAQS. 

In summary, a review of monitoring data, photochemical modeling, and weight of evidence 

analyses generated for the DMA/NFR SIP process suggests that the transport of ozone and 

ozone precursors from Colorado does not cause or significantly contribute to nonattainment in, 

or interfere with maintenance by, any other state with respect to the 0.08 ppm 8-hour ozone 

NAAQS. This analysis does not address ozone transport for the revised 0.075 ppm 8-Hour 

Ozone NAAQS. 

21
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment I Air Pollution Control Division 

2. REFERENCES 

Coats, C.J. Jr. "High-performance algorithms in the Sparse Matrix Operator Kernel Emissions 

(SMOKE) modeling system." Proc. Ninth AMS Joint Conference on Applications ofAir 

Pollution Meteorology with AWMA. Amer. Meteor. Soc., Atlanta, GA, 584-588. 1996. 

ENVIRON. User's Guide - Comprehensive Air Quality Model with Extensions - Version 

4.40. ENVIRON International Corporation, Novato, CA http://www.camx.com. February 

2008. 

Loomis, C., J. Wilkinson, J. Haasbeek, A. Pollack and M. Jansen. 2005. "ConCEPT ­

Consolidated Community Emissions Processing Tool, An Open-Source Toolfor the Emissions 

Modeling Community." Presented at the 14th International Emission Inventory Conference 

"Transforming Emission Inventories - Meeting Future Challenges Today", Las Vegas, 

Nevada, April 11- 14. <http://w~w.epa.gov/ttn/chief/conference/eiI4/session11/loomis.pdt>

MacDonald, C., Miller, D., Raffuse, S., 2006. Regional and Local Contributions to Peak Local 

Ozone Concentrations in Six Western Cities. Sonoma, Technology, Inc., Petaluma, CA. 

Prepared for WESTAR Council ofGovernments.. May 16 

Morris R., E. Tai, Tanarit Sakulyanontvittaya, D. McNally and C. Loomis. 2008a. 2010 Ozone 

Projectionsfor the 2010 Base Case and 2010 Sensitivity Tests and 2010 Ozone Source 

Apportionment Modelingfor the Denver 8-Hour Ozone State Implementation Plan. ENVIRON 

International Corporation, Novato, California. Prepared for Denver Regional Air Quality 

Council (RAQC), Denver, Colorado. September 8. 

Morris R., E. Tai, Tanarit Sakulyanontvittaya, D. McNally and C. Loomis. 2008b. 2010 Ozone 

Attainment Demonstration Modelingfor the Denver 8-Hour Ozone State Implementation Plan 

Control Strategy. ENVIRON International Corporation, Novato, California. Prepared for 

Denver Regional Air Quality Council (RAQC), Denver, Colorado. September 22. 

Morris, R.E., G.E. Mansell, E. Tai, D.A. McNally and T. W. Tesche. 2004a. Air Quality 

Modeling Analysisfor the Denver Early Action Compact: Ozone Source Apportionment 

Modelingfor the Denver EAC. Prepared for the Colorado Department of Health and 

Environment and Denver Regional Air Quality Council, Denver, Colorado. Prepared by 

ENVIRON International Corporation, Novato, CA. May 31 .. 

22
 

DRAFT - State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i) - Interstate Transport Regarding 8-Hour Ozone
 
RECEIVED 

~OV 2"] 2009 

AlRUUALlTY 

~nCCMo\lSSlOi' 

BEFORE THE AIR QUALITY CONTROL COMMISSION, STATE OF COLORADO 

In the Matter of Proposed Revisions to Ambient Air Quality Standards Regulation, Regulation
 

Numbers 3, 7, and 11 for the Denver Metropolitan and North Front Range Ozone Action Plan
 

JOINT RESPONSE IN SUPPORT OF MOTION TO BIFURCATE BY ANADARKO 

PETROLEUM CORPORATION, NOBLE ENERGY, INC., and WILLIAMS 

PRODUCTION RMT COMPANY 

Anadarko Petroleum Corporation ("Anadarko"), Noble Energy, Inc. ("Noble"), and 

Williams Production RMT Company ("Williams") (collectively the "Well Operators") jointly 

submit to the State of Colorado Air Quality Control Commission ("Commission") this Response 

in Support of the Colorado Department of Public Health and Environment, Air Pollution Control 

Division's ("Division") Motion to Bifurcate the Interstate Transport SIP Revision ("Motion to 

Bifurcate"), and state as follow: 

1.	 On November 13, 2008, the Division filed its Motion to Bifurcate with the Commission 

requesting that the Interstate Air Pollutant Transport State Implementation Plan 

("Transport SIP") be bifurcated from the present rulemaking process on the proposed 

Ozone Action Plan. 

2.	 The Division's motion is based, in part, upon comments from the U.S. Environmental 

Protection Agency indicating that the Transport SIP should be seperated from the Ozone 

Action Plan because it is a separate element of the State Implementation Plan. 

3.	 In response, the Division has proposed to separate the Transport SIP from the December 

hearing on the Ozone Action Plan, and have the Transport SIP considered during the 

Commission's regular December meeting. 

4.	 The Well Operators support the Division's Motion to Bifurcate as it well help to further 

narrow the numerous issues to be resolved by the Commission during the hearing on the 

Ozone Action Plan. 

Therefore, the Well Operators respectfully request that the hearing officer grant the Division's 

Motion to Bifurcate, and issue an order bifurcating the Transport SIP from the Ozone Action 

Plan proceedings and scheduling the Transport SIP for hearing during the Commission's regular 

December meeting. 

#879403.2 
Dated this 21st day of November, 2008.
 

Respectfully submitted,
 

sl John R. Jacus
 

John R. Jacus, Esq. 

Todd A. Weaver, Esq. 

Abby J. Gaffney, Esq. 

DAVIS GRAHAM & STUBBS LLP 

1550 Seventeenth Street, Suite 500 

Denver, Colorado 80202 

Telephone: 303-892-9400 

Facsimile: 303-893-1379 

john.jacus@dgslaw.com 

todd.weaver@dgslaw.com 

abby.gaffney@dgslaw.com 

ATIORNEYS FOR ANADARKO PETROLEUM 

CORPORATION, NOBLE ENERGY, INC., AND 

WILLIAMS PRODUCTION RMT COMPANY 

-2­
CERTIFICATE OF SERVICE 

I hereby certify that a true and correct copy of the attached JOINT RESPONSE IN 

SUPPORT OF MOTION TO BIFURCATE BY ANADARKO PETROLEUM 

CORPORATION, NOBLE ENERGY, INC., and WILLIAMS PRODUCTION RMT 

COMPANY was filed and served by electronic mail on the 21st day of November, 2008, upon 

the following: 

Air Quality Control Commission 

Barbara Roberts, barbarawroberts@gmail.com 

Ashley Campsie, ashley.campsie@ch2m.com 

Rad Byerly, hrbyerly@gmail.com 

Douglas Lempke, douglas.lempke@state.co.us 

Theresa Martin, theresa.martin@state.co.us 

North Front Range Metropolitan Planning 

Organization 

Suzette Mallette, smallette@nfrmpo.org 

Regional Air Quality Council 

Kenneth Lloyd, klloyd@raqc.org 

Orf & Orf, P.c., law@orfco.net 

Ted Orf 

Dianna L. Orf 

for Colorado Mining Association 

Colorado Petroleum Association 

Stan Dempsey, Jr. 

stan @coloradopetroleumassociation.org 

Denver Regional Council of Governments 

Steve Cook, scook@drcog.org 

Air Pollution Control Division 

Mike Silverstein, mike.silverstein@state.co.us 

Kirsten King, kirsten.king@state.co.us 

Office of the Attorney General 

Jerry Goad, jerry.goad@state.co.us 

William Allison, william.allison@state.co.us 

Thomas Roan, tom.roan@state.co.us 

Richard L. Griffith, ricklgrif@aol.com 

for Colorado Ethanol Group, including: ERAS, 

Inc.; Pacific Ethanol, Inc.; Sterling Ethanol LLC; 

and Yuma Ethanol LLC 

Fulbright & Jaworski LLP 

Kenneth A. Wonstolen, 

kwonstolen @fulbright.com 

Benjamin Vetter, bvetter@fulbright.com 

for Colorado Oil & Gas Association 

Meg Collins, meg.collins@coga.org 

Carver Schwarz McNab & Bailey, LLC 

Jeffrey W. Schwarz, jschwarz@cksmb.com 

for DCP Midstream, LP 

Daniel J. Schnee, daniel.schnee@elpaso.com 

for EI Paso Western Pipelines consisting of: 

Colorado Interstate Gas Company; EI Paso Natural 

Gas Company; Wyoming Interstate Company, 

Ltd.; Cheyenne Plains Gas Pipeline Company, 

L.L.c.; and Mojave Pipeline Company; who are all 

subsidiaries of: The EI Paso Corporation 
Holme Roberts & Owen LLP 

Colin G. Harris, colin.harris@hro.com 

for EnCana Oil & Gas (USA) Inc. 

Diane M. Blieszner, 

diane.blieszner@EnCana.com 

Hale Friesen, LLP 

Allan L. Hale, ahale@halefriesen.com 

Amanda A. Bradley, abradley@halefriesen.com 

Matthew W. Spengler, 

mspengler@halefriesen.com 

for Environmental Systems Products, Inc. 

Faegre & Benson, LLP 

Linda L. Rockwood, lrockwood@faegre.com 

Eric J. Triplett, etriplett@faegre.com 

for Public Service Company of Colorado d/b/a 

Xcel Energy 

Lauren C. Buehler, 

lauren.c.buehler@xcelenergy.com 

WildEarth Guardians 

Jeremy Nichols, 

jnichols@wildearthguardians.org 

Environmental Defense Fund, Rocky Mountain 

Office 

Kevin Lynch, klynch@edf.org 

Boulder County Public Health 

Pamela H. Milmoe, 

pmilmoe@bouldercounty.org 

Denver Environmental Health 

Gregg Thomas, gregg.thomas@denvergov.org 

Sabrina M. Williams, 

sabrina.williams@denvergov.org 

for Local Government Coalition representing: 

Denver Environmental Health; Boulder County 

Public Health; City of Aspen; and City of Boulder 

Suncor Energy (U.S.A.) Inc. 

Michael E. Korenblat, mkorenblat@suncor.com 

Jay Christopher, jchristopher@suncor.com 

sf Christine M. Thompson 

-2­
RECEIVED 

BEFORE THE AIR QUALITY CONTROL COMISSION 

STATE OF COLORADO ~OV 2 j 2008 

AIR QUALITY 

-----------------------------.......;;:COlQaQlmfll(l.. COMMISSOl
 

WILDEARTH GUARDIANS' RESPONSE IN OPPOSITION TO THE AIR 

POLLUTION CONTROL DMSION'S MOTION TO BIFuRcATE THE 

INTERSTATE TRANSPORT SIP REVISION 

IN RE: PROPOSED REVISIONS TO AMBIENT AIR QUALITY STANDARDS 

REGULATION, REGULATION NUMBERS 3, 7, AND 11 FOR THE DENVER 

METROPOLITAN AND NORTH FRONT RANGE AREA OZONE ACTION PLAN 

The Colorado Department of Public Health and Environment, Air Pollution 

Control Division ("Division"), by and through the Colorado Office of Attorney General, 

has moved the Commission to bifurcate these proceedings by (I) separating the Interstate 

Air Pollutant Transport component of the Colorado SIP ("Transport SIP") from the 

DenverlNorth Front Range Ozone component of the SIP and (2) considering the 

Transport SIP in a separate hearing during the Commission's December meeting. 

WildEarth Guardians opposes the Division's Motion to Bifurcate. As an initial 

matter, we so no reason that the current proposal before the Commission needs to be 

bifurcated for purposes of administrative convenience. In its motion, the Division has 

asked the Commission to hold two separate hearings on the bifurcated SIP components at 

the very same December meeting. In essence, this means that the parties will be required 

to produce the very same witnesses, and engage in examination and cross-examination of 

these witnesses, twice. This makes little sense from the standpoint of efficiency. 

Moreover, it undermines the hearing with regards to ensuring adequate fact-finding and 

public participation. In reality, the two elements of the proposed Colorado SIP raise 

very similar questions for the Commission to consider, e.g., whether the Division has 

adequately modeled sources ofVOCs and NOx in the DenverlNorth Front Range both to 

assure timely attainment of the ozone NAAQS in the region and to assure that these very 

same sources are not contributing to violations ofNAAQS or interfering with NAAQS 

attainment in downwind states. The Commission and parties to the hearing should be 

given the opportunity to examine these related issues within the same hearing and at the 

same time. 

Second, the proposed bifurcation may result in the submission of a SIP that 

violates federal law. Section llO(a)(2) of the federal Clean Air Act ("CAA"), 42 U.S.c. § 

741O(a)(2), states in relevant part that: 
Each implementation plan submitted by a State under this 

chapter shall be adopted by the State after reasonable notice 

and public hearing. Each such plan shall­

(A) included enforceable emission limitations and other 

control measures ... [and] 

(C) include a program for the enforcement [of such] 

measures ... to assure that national ambient air quality 

standards are achieved ... [and] 

(D) contain adequate provisions ­

(i) prohibiting, consistent with the provisions of this 

subchapter, any source or other type of emissions 

activity within the State from emitting any air pollutant 

in amounts which will­

(I) contribute significantly to nonattainment in, or 

interfere with maintenance by, any other State with 

respect to any such national primary or secondary 

ambient air quality standard, or 

(II) interfere with measures required to be included in 

the applicable implementation plan for any other 

State under part C of this subchapter to prevent 

significant deterioration of air quality or to protect 

visibility ... 

WEG believes that these provision of the federal CAA require that the State 

submit a single proposed SIP revision to the Federal Environmental Protection Agency 

("EPA") that can ensure both future attainment of the national ambient air quality 

standard for ozone and that emission sources located within the DenverlNorth Front 

Range attainment air are not contributing to violations of NAAQS or interfering with 

NAAQS attainment in downwind states. A submission to EPA of only one of these 

required SIP elements would be incomplete, and the SIP proposal could not be timely 

considered by EPA under the provisions of the court-approved settlement agreement in 

Rocky Mountain Clean Air Action v. EPA, Civ. No. 07-1012 (D.C. Cir. 2006). See 42 

U.S.c. § 741O(K)(1); 40 C.F.R. Part 51,. App. V. 

Bifurcation of the proposed SIP revision is particularly problematic for purposes of 

compliance with the federal CAA because it can potentially lead to the approval by the 

State of only one of the two proposed elements of the SIP. This may occur, for instance, 

because the Commission chooses to adopt only one of the elements in December either 

2
 
because of time constraints at hearing or because the Division has not demonstrated that 

one of the elements is adequate under state or federal law. Similarly, even if both 

elements are adopted by the Commission, the Colorado legislature could choose to 

exercise its authority pursuant to state law to disapprove either the Ozone SIP or 

Transport SIPs alone. In either case, the granting of the motion to bifurcate potentially 

jeopardizes the timely approval of the proposed SIP by EPA because the state will not be 

able to submit a complete SIP revision in compliance with Section 110 ofthe CAA. 

Finally, in its motion the Division suggests that the motivation for requesting 

bifurcation stems from a comment from EPA that the "Transport SIP has deficiencies ... 

and should be separated from the Ozone SIP." While it may be true that, as it stands, the 

transport component of the SIP has legal deficiencies, separating it from the Ozone SIP 

will not, for reasons stated above, ensure compliance with the CAA. More importantly, 

the EPA has statutory tools available to it to address a proposed SIP in which one or 

more elements are deficient. Specifically, Section 11O(k)(3) provides the EPA authority 

to issue a full or partial approval (and disapproval) of a SIP submission. In other words, 

there is no reason for the State to jeopardize compliance with the CAA merely because 

one portion of the proposed SIP revision may not ultimately be approvable. EPA has 

sufficient legal authority to address that concern when the time comes for its evaluation of 

the SIP. 

In conclusion, for the foregoing reasons WildEarth Guardians requests that the 

Commission deny the Division's Motion to Bifurcate. 

Respectfully submitted this 21 st day of November 2008. 

AND 

Michael R. Harris 

Asst. Professor of Law & Director 

ENVIRONMENTAL LAW CLINIC 

UNIVERSITY OF DENVER 

STURM COLLEGE OF LAW 

3 
EPA Comments 

No Comments 
Public Comments 

No Comments 
Adopted Statement ofBasis,
 

Specific Statutory Authority and Purpose
 
Statement of Basis, Specific Statutory Authority and Purpose 

THIS STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND ~URPOSE SUPPORTS REVISIONS 

TO COLORADO'S IMPLEMENTATION PLAN REGARDING THE INTERSTATE TRANSPORT OF AIR 

POLLUTANTS (HEREINAFTER "INTERSTATE TRANSPORT SIP"). THESE REVISIONS APPLY TO 

COLORADO'S STATE IMPLEMENTATION PLAN ONLY AND DO NOT REVISE ANY REGULATION. 

THEREFORE, THIS STATEMENT IS NOT REQUIRED BY THE ADMINISTRATIVE PROCEDURES ACT. 

NEVERTHELESS, THE COMMISSION OFFERS THIS STATEMENT TO FURTHER THE UNDERLYING 

OBJECTIVES OF THE APA AND THE COLORADO AIR POLLUTION PREVENTION AND CONTROL ACT. 

BASIS 

THE AIR QUALITY CONTROL COMMISSION HAS ADOPTED REVISIONS TO THE INTERSTATE 

TRANSPORT SIP TO ADDRESS COMMENTS FROM THE UNITED STATES ENVIRONMENTAL 

PROTECTION AGENCY (EPA) FINDING THE SIP DEFICIENT. 

IN FEBRUARY OF 2007 THE COMMISSION ADOPTED AN INTERSTATE TRANSPORT SIP FOR OZONE 

AND PM2.5. THIS SIP WAS TRANSMITTED TO EPA IN JUNE OF 2008. SINCE THAT SIP PRECEDED THE 

2007 OZONE SEASON, IT DID NOT REFLECT THE MONITORING RESULTS FROM THAT PERIOD, 

INCLUDING THE VIOLATION OF THE 1997 GROUND-LEVEL OZONE NATIONAL AMBIENT AIR QUALITY 

STANDARDS (NAAQS) AND EPA's SUBSEQUENT DESIGNATION OF NONATTAINMENT FOR THE 

DENVER METRO AREA AND NORTH FRONT RANGE (DMAINFR). EPA OFFERED INFORMAL 

COMMENTS ON THE INTERSTATE TRANSPORT SIP, OPINING ON THIS AND OTHER PERCEIVED 

DEFICIENCIES. IN RESPONSE, THE COMMISSION ADOPTED THE FOREGOING REVISIONS TO ADDRESS 

DEFICIENCIES PERTAINING TO OZONE. 

STATUTORY AUTHORITY 

THE STATUTORY AUTHORITY FOR THESE REVISIONS IS SET FORTH IN § 25-7-105(1), C.R.S. OF THE 

COLORADO AIR POLLUTION PREVENTION AND CONTROL ACT ("ACT"), WHICH AUTHORIZES THE 

COMMISSION TO ADOPT A STATE IMPLEMENTATION PLAN THAT MEETS ALL REQUIREMENTS OF THE 

CLEAN AIR ACT. 

PURPOSE 

THE PURPOSE OF THIS INTERSTATE TRANSPORT SIP REVISION IS TO ADDRESS EPA COMMENTS THAT 

THE SIP DOES NOT ADEQUATELY ADDRESS ANY ADVERSE IMPACTS THE DMAINFR NONATTAINMENT AREA MAY HAVE ON OTHER STATES' COMPLIANCE WITH THE OZONENAAQS. 

PURSUANT TO 42 U.S.c. § 741 0(A)(2)(D)(I), COLORADO'S INTERSTATE TRANSPORT SIP MUST 

DEMONSTRATE, AMONG OTHER THINGS, THAT COLORADO'S AIR POLLUTION SOURCES WILL NOT 

CONTRIBUTE SIGNIFICANTLY TO NONATTAINMENT, OR INTERFERE WITH MAINTENANCE BY, ANY 

OTHER STATE OF THE OZONE NAAQS. THE COMMISSION HAS REVISED THE OZONE TRANSPORT 

SECTION OF THE INTERSTATE TRANSPORT SIP TO INCLUDE ANALYSIS, MONITORING AND MODELING 

INFORMATION DEMONSTRATING THAT COLORADO, INCLUDING THE DMAINFR NON-ATTAINMENT 

AREA, DOES NOT CONTRIBUTE SIGNIFICANTLY TO NONATTAINMENT OR INTERFERE WITH 

MAINTENANCE BY ANY OTHER STATE WITH RESPECT TO THE 0.08 PPM OZONE NAAQS. 
IN A SEPARATE ACTION, THE COMMISSION HAS ADOPTED THE OZONE ATTAINMENT PLAN TO 

ADDRESS EPA's NON-ATTAINMENT DESIGNATION OF THE DMA/NFR AREA. THE OZONE 

ATTAINMENT PLAN AND THE INTERSTATE TRANSPORT PLAN, TOGETHER, FORM THE BASIS FOR A 

CONCLUSION THAT COLORADO'S SIP SATISFIES CLEAN AIR ACT REQUIREMENTS PERTAINING TO 

GROUND-LEVEL OZONE. 
Adopted Language by the Commission
 
State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(l)
 

Interstate Transport Regarding the 1997 8-Hour Ozone Standard
 

December 9, 2008 

Colorado Department of Public Health and Environment 

Air Pollution Control Division 

4300 Cherry Creek Drive South 

Denver, Colorado 80246 

Adopted by the Air Quality Control Commission
 

December 12,2008
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

j 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table of Contents
 

1. OZONE-SPECIFIC PROVISIONS TO MEET THE REQUIREMENTS OF CAA 11O(A)(2)(D)(I)(I)­

IN:rERSTATE TRANSPORT 1 

1.1. INTRODUCTION I 

1.2. COLORADO OZONE MONITORING NETWORK 2 

1.3. OZONE MONITORING NETWORK IN NEARBY STATES 7 

1.4. OZONE TRANSPORT CONCLUSIONS FROM THE DMAINFR PHOTOCHEMICAL MODELING 10 

1.4.1. Emission Inventories and 2006 and 2010 Base Case II 

1.4.2. Discussion 0/2010 Base Case CAMx Modeling Results 15 

1.5. DENVER METRO AREAlNORTH FRONT RANGE OZONE NONATTAINMENT AREA CONTRIBUTION TO 

DOWNWIND LOCATIONS 18 

1.6. SECTION llO(A)(2)(D)(J)(I) - OZONE TRANSPORT CONCLUSIONS 20 

2. REFERENCES 22 

List of Tables 

Table 1: 2008 I-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008) .4 

Table 2: 2008 8-Hour Ozone Monitored Concentration (updated through Sept. 30,2008) 5 

Table 3: 8-Hour Design Value Using the 3-Year (2006-2008) Average of the Fourth Maximum 

Ozone Concentration 6 

Table 4: 2005-2007 3-Year Fourth Highest Average Monitoring Concentrations from Kansas, 

Nebraska, New Mexico, Utah and Wyoming 7 

Table 5. Base Case Inventories for 8-Hour Ozone DMAlNFR NAA Photochemical Modeling 14 

List of Figures 

Figure 1. Location of Front Range Ozone Monitors 2 

Fig~re 2. Location of Statewide Ozone Monitors 3 

Figure 3: 8-Hour Ozone Nonattainment Areas 9 

Figure 4. Nested 12/4 km modeling domains for the Denver CAMx air quality and SMOKE 

emissions modeling : 10 

Figure 5. Projected 2010 8-hour ozone Design Values (DVF) 15 

Figure 6. Rocky Flats North source apportionment for 29 July including boundary conditions 16 

Figure 7: Spatial extent of the 8-hour ozone concentrations that occurred between lOam and 6pm 

local time on June 27, 2002 through July 1, 2002 19 

ii 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

iii
 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment I Air Pollution Control Division 

1. Ozone-Specific Provisions to Meet the Requirements of 

CAA 11 O(a)(2)(D)(i)(I) - Interstate Transport 

1.1. Introduction 

The purpose of this document is to provide a plan for the State of Colorado to meet the 

requirements of the Clean Air Act Section 110 (a)(2)(D)(i)(I) Interstate Transport 

requirements regarding the 0.08 parts per million (ppm) 8-Hour Ozone National Ambient 

Air Quality Standard (NAAQS). This addresses the applicable components of 

110(a)(2)(D)(i)(I) demonstrating adequate provisions to prevent emissions from Colorado 

from interfering with attainment or maintenance of the federal ozone NAAQS in any other 

state. This analysis does not address ozone transport for the revised 0.075 ppm 8-Hour 

Ozone NAAQS. 

This document replaces the section titled "Ozone-Specific Provisions" in the document 

"State of Colorado Implementation Plan to Meet the Requirements of Clean Air Act 

Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone and PM25 . 

NAAQS." 

Currently, the Denver area is the only area in U.S. Environmental Protection Agency 

(EPA) Region VIII that is designated as nonattainment for the 8-hour ozone NAAQS of 

0.08 ppm. . 

In this report, relevant information from the Denver Metropolitan Area and North Front 

Range (DMAlNFR) 8-hour Ozone State Implementation Plan (SIP) process, the Denver 

Early Action Compact (EAC) process, ambient ozone data for Colorado, ambient ozone 

data for nearby states from the EPA Air Quality System (AQS) database, and other 

information is used to demonstrate that Colorado does not contribute significantly to 

nonattainment in, or interfere with maintenance by, any other state with respect to the 0.08 

ppm ozone NAAQS. 

1
 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section J10 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.2. Colorado Ozone Monitoring Network 

The 2007/2008 ozone ambient air monitoring network in the Denver area and along the 

northern Front Range consists of 13 stations operated by the Colorado Air Pollution 

Control Division (APCD) and one station operated by the National Park Service (NPS) in 

Rocky Mountain National Park. There have been other stations that have operated in the 

past. The geographical distribution of the Front Range monitors is presented in Figure 1. 

As shown in Figure 1, the ozone monitors are primarily located in urbanized areas along 

the Front Range corridor. The monitors are located in areas where the highest ozone 

concentrations have been monitored historically and where elevated ozone is expected to 

occur. High ozone concentrations along the Front Range occur near the areas with high 

emissions density and dense population. In addition, elevated ozone is observed along 

elevated terrain to the west of the DMAlNFR Nonattainment Area. All of these monitors 

are designated by the U.S. Environmental Protection Agency as "equivalent" analyzers and 

follow all quality assurance requirements as specified in 40 CFR Part 58, Appendix A. 

simla'" Ramah,,"#," .//" 

Figure 1. Location of Front Range Ozone Monitors 

2
 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Figure 2 shows other ozone monitoring sites that exist in Colorado for 2008. These are 

operated by either Colorado, the Southern Ute Tribe, or various Federal agencies. All of 

these sites use monitors that are designated as "equivalent" analyzers by the U.S. 

Environmental Protection Agency. As shown, most of the sites are in the southwest comer 

of Colorado, either within or near the San Juan oil and gas development area. 

.­" 

_0 

(noftMllfl 

.,,"":~ V<"!:~'" """" (,k..,' J 

w.-.... (#} <?­ ., -,. )'~:.. ,,~

Figure 2. Location of Statewide Ozone Monitors 

Table I, Table 2, and Table 3 present the monitoring data for the DMA/NFR NAA 

monitoring sites (including the NPS Rocky Mountain National Park monitoring site) as 

well as for other sites in Colorado. In Table 3, the fourth maximum 8-hour ozone 

concentrations along with the 3-year average of the fourth maximum concentrations at each 

site are presented. As shown in both Table I and Table 3, the Denver area is currently 

meeting the 8-hour and former I-hour ozone NAAQS for all sites, except for the 8-Hour 

NAAQS at Rocky Flats North with a design value of 0.86 ppm. 

3
 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(1) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table I: 2008 I-Hour Ozone Monitored Concentration (updated through Sept. 30,2008) 

AQS 

Number Site Name 

1st Max 

I-Hour 

(ppm) 

Date 

1st Max 

I-Hour 

2nd Max 

I-Hour 

(ppm) 

Date 

2nd Max 

I-Hour 

3rd Max 

I-Hour 

(ppm) 

Date 

3rd Max 

I-Hour 

4th Max 

I-Hour 

(ppm) 

Date 

4th Max 

I-Hour 

08-001-3001 Welby 0.100 08/29 0.095 08/05 0.092 07/10 0.089 06/20 

08-005-0002 * Highland 0.065 04/04 0.064 04/08 0.064 04/18 0.062 04/19 

08-013-0011 S. Boulder Creek 0.089 07/10 0.089 07/25 0.086 07116 0.085 05/31 

08-031-0014 Carriage 0.094 08/05 0.090 08/29 0.089 07/10 0.085 06/20 

08~031-0025 ** Denver - Animal 

Shelter 0.100 07/10 0.098 08/05 0.087 06/20 0.087 08/24 

08-035-0004 Chatfield State Park 0.101 07/10 0.098 06/20 0.095 08/29 0.092 08/24 

08-041-00 13 Colo. Spgs. -

Academy 0.085 OS/24 0.083 07/10 0.082 08/06 0.080 07/18 

08-041-0016 Manitou Springs 0.087 OS/24 0.085 08/06 0.083 07/10 0.083 07/11 

08-045-0012 ** Rifle - Health 0.081 07/09 0.080 07/10 0.075 08/19 0.074 07/11 

08-059-0002 Arvada 0.093 08/05 0.093 08/29 0.092 07/10 0.088 07/25 

08-059-0005 Welch 0.102 07/10 0.090 06/20 0.088 08/05 0.088 08/29 

08-059-0006 Rocky Flats - N 0.088 07/10 0.088 07/18 0.088 08/29 0.087 07/02 

08-059-0011 NREL 0.097 08/29 0.093 07/10 0.092 08/05 0.092 08/24 

08-067-7001 *** So. UteIgnacio 0.076 06/04 0.075 ----05/31 0.073 05/03 0.072 05/3 

08-067-7003 *** So. UteBondad 0.080 06/04 0.078 05/31 0.077 OS/27 0.071 04/21 

08-067-???? USFS - Shamrock 0.081 06/04 0.079 06/10 0.077 02/29 0.077 05/30 

08-069-0007 Rocky Mountain 

Nat'l Park 0.092 07/09 0.090 07/31 0.090 08/28 0.085 OS/22 

08-069-0011 Ft. Collins - West 0.093 08/19 0.092 07/09 0.092 07/18 0.088 07124 

08-069-1004 Ft. Collins - CSU 0.082 08/19 0.080 07/09 0.079 08/30 0.078 07124 

08-077-0020 ** Palisade - Water 0.081 07/09 0.079 07/10 0.075 07/08 0.074 07/05 

08-083-0006 ** Cortez 0.078 07/23 0.074 07113 0.072 08/05 0.071 07/25 

08-083-0101 Mesa Verde Nat'l 

Park 0.075 05/01 0.075 06/04 0.074 05/31 0.072 04/30 

08-123-0009 Greeley - Weld 

Tower 0.094 08/20 0.092 07/24 0.089 08/01 0.087 08/04 

NOTES: 

* Highland site shut down on 4/21/08 for approx. 6-months.
 

** Denver - Animal Shelter site commenced on 4/22/08, Rifle - Health commenced on 6/20/08,
 

Palisade - Water commenced on 5/30/08 and Cortez commenced on 6/17/08. 

*** Southern Ute sites data only thru 6/30/08. 

4
 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table 2: 2008 8-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008) 

AQS 

Number Site Name 

1st Max 

8-Hour 

(ppm) 

Date 

1st Max 

8-Hour 

2nd Max 

8-Hour 

(ppm) 

Date 

2nd Max 

8-Hour 

3rd Max 

8-Hour 

(ppm) 

Date 

3rd Max 

8-Hour 

4th Max 

8-Hour 

(ppm) 

Date 

4th Max 

8-Hour 

08-001-3001 Welby 0.085 07/10 0.083 08/29 0.077 07/18 0.076 06/20 

08-005-0002 • Highland 0.062 04/04 0.060 04/08 0.060 04/18 0.059 04/05 

08-013-00 II S. Boulder Creek 0.080 07/10 0.076 05/31 0.076 07/09 0.076 07/18 

08-031-0014 Carriage 0.081 07/10 0.075 08/29 0.073 06/20 0.072 07/26 

08-031-0025 .. Denver - Animal 

Shelter 0.086 07/10 0.072 08/29 0.071 07/13 0.070 07/26 

08-035-0004 Chatfield State Park 0.090 07/10 0.082 06/30 0.080 06/20 0.080 06/27 

08-041-0013 Colo. Spgs. -

Academy 0.078 OS/24 0.077 07/10 0.073 08/06 0.070 07/18 

08-041-0016 Manitou Springs 0.080 OS/24 0.076 07/10 0.074 07/11 0.072 07/31 

08-045-0012 *II< Rifle - Health 0.076 07/09 0.076 07/10 0.069 08/19 0.066 07/13 

08-059-0002 Arvada 0.081 08/29 0.080 07/10 0.077 06/20 0.074 08/05 

08-059-0005 Welch 0.095 07/10 0.079 06/20 0.077 07/18 0.073 08/19 

08-059-0006 Rocky Flats - N 0.083 07/10 0.080 07/18 0.079 05/31 0.079 08/29 

08-059-00 II NREL 0.085 07/10 0.085 08/29 0.077 06/20 0.076 06/02 

08-067-700 I ... So. UteIgnacio 0.069 06/04 0.067 06/10 0.066 05/10 0.066 06/13 

08-067-7003 ..* So. UteBondad 0.073 06/04 0.067 OS/27 0.067 05/31 0.067 06/05 

08-067-???? USFS - Shamrock 0.074 06/04 0.073 06/10 0.071 06/13 0.069 05/30 

08-069-0007 Rocky Mountain 

Nat'l Park 0.081 07/09 0.077 OS/25 0.077 07/31 0.076 05/31 

08-069-00 II Ft. Collins - West 0.081 07/18 0.079 07/09 0.078 OS/25 0.076 07/24 

08-069-1004 Ft. Collins - CSU 0.070 OS/25 0.070 07/09 0.068 07/18 0.066 05/31 

08-077-0020 ** Palisade - Water 0.077 07/09 0.075 07/10 0.070 05/31 0.070 07/29 

08-083-0006 ** Cortez 0.067 08/02 0.066 07/23 0.065 08/07 0.064 08/05 

08-083-0101 Mesa Verde Nat'l 

Park 0.071 06/04 0.070 04/30 0.069 04/21 0.069 06/10 

08-123-0009 Greeley - Weld 

Tower 0.077 07/24 0.076 08/20 0.075 07/26 0.073 08/01 

NOTES: 

* Highland site shut down on 4/21/08 for approx. 6-months.
 

** Denver - Animal Shelter site commenced on 4/22/08, Rifle - Health commenced on 6/20/08,
 

Palisade - Water commenced on 5/30/08 and Cortez commenced on 6/17/08.

*** Southern Ute sites data only thru 6/30/08. 

5
 

State ofColorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(iXI) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table 3: 8-Hour Design Value Using the 3-Year (2006-2008) Average ofthe Fourth Maximum Ozone 

Concentration . 

Site Name AQS# 

2006 

7 

Maximum 

8-Hour 

Average 

Value (ppm) 

2007 

7 

Maximum 

8-Hour 

Average 

Value (ppm) 

2008 

7 

Maximum 

8-Hour 

Average 

Value (ppm) 

Design Value 

(2006 - 2008) 

3-Year 

Average 

4th Maximum 

Value (ppm) 

Welby 08-001-300 I 0.069 0.070 0.076 0.071 

... Highland 08-005-0002 0.081 0.075 0.059 0.071 

S. Boulder Creek 08-013-0011 0.082 0.085 0.076 0.081 

Carriage 08-03 1-0014 0.072 0.076 0.072 0.073 

.. Denver - Animal 

Shelter 08-03 1-0025 --­ --­ 0.070 ---

Chatfield State Park 08-035-0004 0.086 0.082 0.080 0.082 

USAF Academy 08-041-0013 0.072 0.072 0.070 0.071 

Manitou Springs 08-041-0016 0.076 0.072 0.072 0.073 

...... Rifle - Health 08-045-0012 --­ --­ 0.066 --­

Arvada 08-059-0002 0.082 0.079 0.074 0.078 

Welch 08-059-0005 0.081 0.080 0.073 0.078 

Rocky Flats - North 08-059-0006 0.090 0.090 0.079 0.086 

NREL 08-059-00 II 0.083 0.085 0.076 0.081 

..... So. Ute - Ignacio 08-067-7001 --­ --­ 0.066 --­

..* So. Ute - Bondad 08-067-7003 0.063 0.071 0.067 0.067 

USFS - Shamrock 08-067-71?? 0.074 0.069 0.069 0.070 

Rocky Mountain Nat'l 

Park 08-069-0007 0.076 0.078 0.076 0.076 

Fort Collins - West 08-069-00 II 0.087 0.085 0.076 0.082 

Fort Collins - CSU 08-069-1004 0.078 0.069 0.066 0.071 

** Palisade - Water 08-077-0020 --­ --­ 0.070 --­

** Cortez 08-083-0006 --­ --­ 0.064 --­

Mesa Verde Nat' I Park 08-083-0 I0 I 0.074 0.070 0.069 0.071 

Greeley - Weld Tower 08-123-0009 0.082 0.074 0.073 0.076 

NOTES: 

* Highland site shut down on 4/21108 for approx. 6-months.
 

** Denver - Animal Shelter site commenced on 4/22/08, Rifle - Health commenced on 6/20/08,
 

Palisade - Water commenced on 5/30/08 and Cortez commenced on 6/17/08. 

*** Southern Ute sites data only thru 6/30/08. Ignacio data invalid for 0112005 to 08/2007. 

6 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment I Air Pollution Control Division 

1.3. Ozone Monitoring Network in Nearby States 

Table 4 present 8-hour ozone monitoring data from the surrounding states of Nebraska, Kansas, 

New Mexico, Wyoming, and Utah. Table 4 and show that none ofthe monitors in surrounding 

states exceed the 8-hour ozone standard except for Davis County Utah. Therefore, to the extent 

that the network is representative of all areas, it can be concluded that the DMAlNFR sources do 

not significantly contribute to the 8-hour ozone standard violations at these down wind locations or 

even further downwind. In addition, Colorado does not significantly contribute to violations 

upwind including Davis County Utah. Utah's 8-hour proposed 8-hour maintenance plan for the 

1997 8-hour ozone standard does not suggest that Colorado interferes with the maintenance of the 

standard in Davis County Utah. 

Table 4: 2005-2007 3-Year Fourth Highest Average Monitoring Concentrations from Kansas, Nebraska, 

New Mexico, Utah and Wyoming 

Site ID State County 

EPA 

Ree:ion 

2005 

8-hr 

Ozone 

4th Max 

(ppm) 

2006 

8-hr 

Ozone 

4th Max 

(ppm) 

2007 

8-hrOzone 

4th Max 

(ppm) 

3-yr 

Avg. of 

4th MaxI 

(ppm) 

20-045-0004 KS Douglas 7 0.073 0.081 End 2007 N/A 

20-091-0010 KS Johnson 7 0.081 0.076 0.071 0.076 

20-103-0003 KS Leavenworth 7 0.077 0.074 0.080 0.077 

20-107-0002 KS Linn 7 0.075 0.079 0.070 0.074 

20-173-0001 KS Sedgwick 7 0.065 0.065 0.059 0.063 

20-173-0010 KS Sedgwick 7 0.074 0.073 0.060 0.069 

20-191-0002 KS Sumner 7 0.078 0.080 0.070 0.076 

20-195-0001 KS Trego 7 0.071 0.076 0.068 0.071 

20-209-0021 KS Wyandotte 7 0.079 0.081 0.073 0.077 

31-055-0028 NE Douglas 7 0.069 0.072 0.066 0.069 

31-055-0032 NE Douglas 7 0.067 0.066 0.056 0.063 

31-055-0035 NE Douglas 7 0.070 0.067 0.061 0.066 

3 1-1 09-00 16 NE Lancaster 7 0.056 0.056 0.054 0.055 

35-001-0019 NM Bernalillo 6 0.073 0.073 0.070 0.072 

35-001-0023 NM Bernalillo 6 0.072 0.073 0.069 0.071 

35-001-0024 NM Bernalillo 6 0.074 0.074 0.068 0.072 

35-001-0027 NM Bernalillo 6 0.073 0.072 0.071 0.072 

35-001-0029 NM Bernalillo 6 0.071 0.070 0.067 0.069 

35-001-1012 NM Bernalillo 6 0.077 0.047 0.074 0.066 

35-001-1013 NM Bernalillo 6 0.077 0.071 0.071 0.073 

35-001-1014 NM Bernalillo 6 0.072 0.072 0.064 0.069 

35-013-0008 NM Dona Ana 6 0.070 0.072 0.068 0.070 

35-013-0017 NM Dona Ana 6 0.070 0.073 0.070 0.071 

35-013-0020 NM Dona Ana 6 0.072 0.072 0.068 0.070 

35-013-0021 NM Dona Ana 6 0.076 0.080 0.076 0.077 

35-013-0022 NM Dona Ana 6 0.070 0.073 0.073 0.072 

35-013-0023 NM Dona Ana 6 0.066 0.070 0.062 0.066 

7 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(l) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table 4 (continued) 2005-2007 3-Year Fourth Highest Average Monitoring Concentrations from Kansas, 

Nebraska, New Mexico, Utah and Wyoming 

Site ill State County 

EPA 

Reeion 

2005 

8-hr 

Ozone 

4th Max 

(ppm) 

2006 

8-hr 

Ozone 

4th Max 

(ppm) 

2007 

8-hrOzone 

4th Max 

(ppm) 

3-yr 

Avg. of 

4th Max 

(ppm) 

35-015-1005 NM Eddy 6 0.067 0.076 0.066 0.069 

35-017-1003 NM Grant 6 0.071 0.067 0.062 0.066 

35-025-0008 NM Lea 6 0.074 0.075 0.064 0.071 

35-029-0003 NM Luna 6 Start 2006 0.053 0.062 N/A 

35-043-1001 NM Sandoval 6 0.069 0.064 0.063 0.065 

35-043-1003 NM Sandoval 6 0.075 0.074 0.071 0.073 

35-043-9004 NM Sandoval .6 0.076 0.072 0.067 0.071 

35-045 -0009 NM San Juan 6 0.075 0.063 0.069 0.069 

35-045-0018 NM San Juan 6 Start 2006 0.079 0.079 N/A 

35-045-1005 NM San Juan 6 0.072 0.071 0.073 0.072 

49-003-0003 UT Box Elder 8 0.079 0.078 0.077 0.078 

49-003-7001 UT Box Elder 8 0.075 0.076 0.078 0.076 

49-005-0004 UT Cache 8 0.069 0.073 0.074 0.072 

49-011-0004 UT Davis 8 0.092 0.082 0.082 0.085 

49-035-0003 UT Salt Lake 8 0.083 0.084 0.082 0.083 

49-035-2004 UT Salt Lake 8 0.086 0.082 0.082 0.083 

49-035-3006 UT Salt Lake 8 0.082 0.082 0.079 0.081 

49-035-3007 UT Salt Lake 8 0.085 0.080 0.080 0.081 

49-035-3008 UT Salt Lake 8 0.080 0.082 0.079 0.080 

49-037-0101 UT. San Juan 8 0.069 0.070 0.072 0.070 

49-045-0003 UT Tooele 8 0.080 0.079 0.076 0.078 

49-049-0002 UT Utah 8 0.078 0.074 0.075 0.075 

49-049-5008 UT Utah 8 0.080 0.077 0.078 0.078 

49-049-5010 UT Utah 8 0.080 0.079 0.077 0.078 

49-053-0130 UT Washington 8 0.091 0.072 0.071 0.078 

49-057-0007 UT Weber 8 0.081 0.083 0.080 0.081 

49-057-1003 UT Weber 8 0.084 0.083 0.082 0.083 

56-005-0123 WY Campbell 8 0.063 0.072 0.072 0.069 

56-005-0456 WY Campbell 8 0.063 0.065 0.072 0.066 

56-035-0098 WY Sublette 8 0.075 0.069 0.068 0.070 

56-035-0099 WY Sublette 8 0.079 0.072 0.067 0.072 

56-035-0100 WY Sublette 8 0.066 0.074 0.066 0.068 

56-037-0200 WY Sweetwater 8 Start 2006 0.067 0.064 N/A 

56-039-1011 WY Teton 8 0.060 0.069 0.065 0.064 

Figure 3 presents a map of all the U.S. nonattainment areas for the 1997 8-hour ozone 

standard.. Since the surrounding states of Kansas, Nebraska, Wyoming, Utah, and New 

Mexico do not have violations the 8-hour NAAQS for ozone, it can be reasonably 

concluded that Colorado sources do not significantly affect the ozone nonattainment areas 

8
 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

even further downwind such as Dallas-Forth Worth and 81. Louis nonattainment areas. In 

addition, it is unlikely that Colorado would significantly affect nonattainment areas that are 

typically "upwind" such as Las Vegas and Phoenix. However, it is recognized that, under 

the types of synoptic scale meteorological regimes that occur during some regional ozone 

episodes, simple terms like "upwind" and "downwind" may not be applicable. Thus, 

photochemical modeling is needed to study the distribution of ozone under a variety of 

meteorological regimes. 

Nonattainment and Maintenance Areas in the U. S. 

a-hour Ozone Standard 

( \ .: :' I- ~- \ L{\\:.---..--­ j 

~~'..!' -···-r---- ------! -- " - l----­ \-~-~ ! II I

, " 

, -~--~

""'"'·""--L:.---,\~---,-j • I -) I. (' Y

" \ L' \ ----,"-,..--,.;\ , J- '. 'I ' 

• Nonattainmen' A,ea. (263 enti.. ,,,"::'~;"\, (_~~(C-'V'\\ i-' '-. Nonattainment Areas (30 partial counties) \ '\ ' mrJ . . Maintenance Areas (141 entire or partial counties) ""'__\'\.j

Partial counties, those with part of the county designated
 

nonattainment and art attainment, are shown as fuR counties on the rna .
 

Figure 3: 8-Hour Ozone Nonattainment Areas 

9
 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
---

Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.4.	 Ozone Transport Conclusions from the DMAlNFR 

Photochemical Modeling 

The DMAlNFR photochemical model domain was defined on a nested 36-kilometer (km), 

12 km, and a 4 km nested-grid structure. This structure was utilized in conjunction with 

the Comprehensive Air-quality Model with extensions (CAMx) air quality model 

(ENVIRON, 2008). CAMx, SMOKE (Coats, 1996), and CONCEPT MS (Loomis et aI., 

2005) air quality and emissions modeling was performed for the June-July 2006 period. 

Nested 36/12/4 km modeling domains were used in the Denver 8-hour ozone modeling 

study. The CAMx model was first applied to the 36 km continental U.S. domain using 

boundary conditions (BCs) from a global climate air quality model. The CAMx 2006 and 

2010 base case modeling results from the 36 km continental U.S. domain simulation were 

then processed to generate BCs for the CAMx 12/4 km domain (Figure 4) for the 2006 12/4 

km base case and 2010 12/4 km base case and sensitivity simulatioris. The CAMx 

simulations for the 12/4 km domains were run using two-way interactive grid nesting (i.e., 

pollutants can flow back and forth between the 12 km and 4 km domains to account for 

recirculation). The larger 36km domain was selected to address the impact of boundary 

condition uncertainties for the Front Range area of Colorado, as APCD was concerned 

there may be transport from Southern California and Texas. The 12 km grid resolution 

domain essentially covers the central Rocky Mountain States or portions thereof (i.e., 

Arizona, Colorado, New Mexico, Utah and Wyoming.) The 4 km nested-grid covers most 

of the state of Colorado. 

480	 , /	 :

I 

..••.L..._.._	 ; !
 

360...: ~----.

I
 

1- - ----.-.- _ .. -----'1I 

240­ - t .,---£::------r--, 

120	 ----~ -1	 " :... ,

I 

, I I \-.-­

'. 0 -'._.. --.,---""?

I \ -120	 ,

I

, 

\ /	 i 

r-----...--- I , ·240 

I

,	 i I

I	 --- .t---­CAMx4km I 

"	 =~--=-=----=-=-- I

r'/

-360 

\

\,	 ,

I

\,

\	 I 

-480 "	 J "...' 

I H

r) t, 

!:

1/

-600	 ,i i CAMx 12km

I"	 " .. 'I' ":. "I 

-1680-1560-1440-1320-1200-1080 ·960 -840 -720 -600 -480 -360 -240 -120 o 120 240 

\ 

Figure 4. Nested 12/4 km modeling domains for the Denver CAMx air quality and SMOKE emissions 

modeling. 

10 

State ofColorado Implementation Plan to Meet the Requirements of 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.4.1. Emission Inventories and 2006 and 2010 Base Case 

The photochemical modeling for the "2010 base case" emissions scenario perfonned for 

the DMAlNFR Ozone SIP process demonstrates compliance in the Front Range Region 

with the 8-hour 0.08 ppm ozone NAAQS. Control measures in place in 2006 and assumed 

for 2010 include: 

1.	 Federal tailpipe standards and regulations, including those for small engines and 

non-road mobile sources. Credit is taken for these federal requirements but they are 

not part of the Colorado SIP. The credits change from 2006 to 2010 as the United 

States Environmental Protection Agency (EPA) Tier II and low sulfur gasoline 

standards become effective. 

2.	 Air Quality Control Commission Regulation No. ll--covering the Automobile 

Inspection and Readjustment (A.LR.) program in place during the 2006 ozone 

season, which includes an enhanced Inspection/Maintenance (11M). For 2006, a 

maximum of 10% fleet coverage is assumed, and for 2010, a maximum of 50% 

fleet coverage is assumed for the remote sensing clean screen program in the 

Denver metro area (DMA) based on Regulation No. 11. 

3.	 Air Quality Control Commission Regulations No.3, No.6, No.7, and Common 

Provisions--covering gasoline station and industrial source control programs. The 

Common Provisions, Parts A and B of Regulation No.3, and the volatile organic 

compounds (VOC) control requirements of Regulation No.7 are already included 

in the approved SIP. Regulation No.6 and Part C of Regulation No.3 implement 

the federal standards of perfonnance for new stationary sources and the federal 

operating permit program. This reference to Regulation No.6 and Part C of 

Regulation No.3 shall not be construed to mean that these regulations are included 

in the SIP. 

4.	 Since 2004, gasoline sold in the Denver metro area during the summer Reid Vapor 

Pressure (RVP) ozone season (June 1 to September 15) has been subject to a 

national RVP limit of 7.8 pounds per square inch (psi) to reduce fuel volatility. For 

ethanol-blended fuels, the RVP limit is 8.8 psi due to the federal 1.0 psi RVP 

waiver for ethanol. 

Since 1991, gasoline sold in the Larimer and Weld area during the summer ozone 

season (June 1 to September 15) has been subject to a national RVP limit of9.0 psi 

to reduce fuel volatility. For ethanol-blended fuels, the RVP limit is 10.0 psi due to 

the federal 1.0 psi RVP waiver for ethanol. 

For 2006, the RVP of gasoline for the Denver metropolitan portion of 

nonattainment area was determined by survey to be at 8.2 psi, with an ethanol 

market share of 60%, and for the Larimer and Weld portion of the nonattainment 

area the RVP was determined to be 8.4 psi with the same ethanol share of 60%. For 

purposes of the base case 2010 mobile source inventory, the RVP of the base 

II 

State of Colorado Imp lementation Plan to Meet the Requirements of
 

Clean Air Act Section J Io(a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

gasoline is assumed to be 7.8 psi for the Denver metropolitan portion of 

nonattainment area, with an ethanol market share of 85%, and for the Larimer and 

Weld portion of the nonattainment area the RVP was assumed to be 9.0 psi with an 

ethanol share of 25%. 

5.	 The EPA approved the EAC Ozone Action Plan (OAP) on August 19, 2005. The 

OAP included an amendment to Regulation No.7 requiring the reduction of flash 

emissions of volatile organic compounds from condensate collection, storage, 

processing and handling operations by May 1, 2005. This initial rule required the 

installation of air pollution control technology to achieve a system-wide 47.5% 

reduction from uncontrolled emissions of volatile organic compounds from new and 

existing oil and gas exploration and production operations located within the 8-hour 

ozone nonattainment area designated by EPA for operators with total emissions 

greater than 30 tons per year. The 2006 base case estimate was developed from 

actual reported emissions based on the system-wide 47.5% reduction requirement. 

6.	 In February 13,2008, the EPA approved revisions to Regulation No.7 to require 

the system-wide reduction of condensate tank flash VOC emissions of 75% for the 

2007 ozone season by May 1,2007 and 78% reduction for the 2012 ozone season, 

with technology that achieves a 95% reduction in VOC emissions. The 2010 base 

case emissions estimate assumes the 75% system-wide reduction requirement. 

7.	 The effect of EPA final locomotive Tier 3 standards were considered and included, 

where appropriate, in the 2010 area source estimates. Tier 4 locomotive standards 

do not go into effect until 2015 and therefore were not included in the 2010 

inventories. 

All of the inventories in this 8-hour Ozone Attainment SIP were developed using EPA 

approved emissions modeling methods, including EPA's MOBILE6 model and local VMT 

data for on-road mobile source emissions, EPA's non-road model and local demographic 

information for area and off-road sources, and reported actual emissions for point sources. 

Estimates for future emissions are based on the above-mentioned tools and the EPA's 

Economic Growth and Analysis System (EGAS) model for estimating future point sources 

activity, VMT growth for on-road mobile sources, and 2010 and 2012 demographic data 

for off-road and area sources. The technical support document contains detailed 

information on model assumptions and parameters for each source category. 

Highway mobile source emissions are from the ENVIRON Consolidated Community 

Emissions Processing Tool (CONCEPT) model inventory, which is based on DRCOG 

VMT data and MOBILE6 input data provided by APCD and expanded to the entire NAA 

based on VMT from the North Front Range Transportation and Air Quality Planning 

Council and CDOT. 

Non-road source emissions are from the EPA Non-Road Model. This model includes the 

impact of future controls on non-road engines, which is used in equipment such as lawn 

and garden equipment and construction equipment. Oil and gas source emissions are from 

12
 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment I Air Pollution Control Division 

the revised Independent Petroleum Association of Mountain States (lPAMS) inventory, 

and were projected to 20 lOusing the methodology in the IPAMS projection methodology 

document. The IPAMS inventory was sponsored by the IPAMS and is Phase III of a 

regional oil and gas emission inventory for the Inter-Mountain West jointly with the 

Western Regional Air Partnership (WRAP). 

Non-oil and gas area source emissions (including heating, consumer solvent use, aircraft 

and railroads, etc.) are from the 2002 EPA National Emissions Inventory (NEI), grown to 

2006 and 2010 by population growth from data from the State Demographer. Consumer 

solvent emission reductions based on 75% of the per-person reductions listed in the EPA 

May 30, 2007 Emission Reduction Credit Memo were applied to the projected 2010 nonoil and gas area source inventory. A check on the non-oil and gas area sources estimates 

comparing the recently available 2005 NEI emissions data is shown later in this document. 

An inventory completed in 2005 for Denver International Airport (DIA) was used for 

aircraft and airport non-road source emissions from DIA for both 2006 and 2010. 

Non-oil and gas point source emissions were grown to 2010 by the EPA EGAS economic 

model, and by adding sources for which pennits have been issued. 

Emissions of VOC and nitrogen oxides (NOx) from biogenic sources have been generated 

by the Model of Emissions of Gases and Aerosols from Nature (MEGAN) Biogenic 

Emissions Model using land cover data base of biomass type and density and hourly 

meteorology data. The National Center of Atmospheric Research (NCAR) has produced a 

global data base of land use data, the MEGAN Driving Variable Database Version 1.2, for 

use with MEGAN. Surface temperatures are provided by the Mesoscale Meteorological 

Model (MM5) modeling. 

Summaries of the VOC and NOx base case inventories for the nonattainment area for 2006 

and 2010 are presented in Table 5. Emissions of NOx and VOCs are in tons per average 

episode day. Additional detail on the categories of emissions can be found in the TSD. 

Wildfire emissions, though not included in tables, have been considered for the background 

ozone concentrations in the modeling effort. Wildfire emissions can vary significantly on a 

day-to-day basis depending on conditions. 

13
 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

Table 5. Base Case Inventories for 8-Hour Ozone DMAlNFR NAA Photochemical Modeling 

(tons per average episode day) 

2006 2010 

Source Category NOx VOC NOx VOC 

Point Sources 

Electric Generation Units (EGU) 55.6 0.7 58.5 1.6 

External Combustion Boilers 9.5 04 10.0 0.5 

Industrial Processes 12.5 10.2 14.0 11.0 

Petroleum and Solvent Evaporation 0.3 190 0.3 22.0 

Other 3.1 1.8 3.6 2.0 

Point Sources Subtotal 81.0 32.1 86.4 37.0 

Oil & Gas Point & Area Sources 

Condensate Tanks 126.5 129.6 

Other O&G Point Sources 22.6 6.8 23.6 8.6 

Pneumatic Devices (Area Source) 248 31.1 

Unpermitted Fugitives (Area Source) 162 204 

Other Area Sources 17.1 10.8 22.5 13.7 

O&G Point & Area Sources Subtotal 39.7 185.2 46.2 203.3 

Area Sources 

Personal Care Products 7.1 7.0 

Household Products 214 179 

Automotive Aftermarket Products 11.9 13.0 

Architectural Coatings 201 16.8 

Aircraft 74 : 1.3 82 1.5 

Railroad 12.8 : 0.5 13.8 0.6 

Other CoatingslPesticides/Cooking/ Miscellaneous. · 3.9 4.1 

Area Source Subtotal 20.2 : 66.3 22.1 61.0 

Non-Road Mobile Sources 

Agricultural Equipment 70: 0.9 6.3 : 07 

Airport EqUipment 0.7 : 0.1 0.6 : 0.1 

Commercial Equipment 53~ 62 5.1 : 7.0 

Construction and Mining Equipment 35.7 : 55 31.2 : 4.5 

Industrial Equipment 10.5 : 24 6.9 : 14 

Lawn and Garden Equipment (Commercial) 9.4 : 35.9 8.9 ! 28.1 

Lawn and Garden Equipment (Residential) 1.2 : 7.5 1.2 : 11.8 

Boats/Recreational EquipmenUMiscellaneous 0.7 : 6.9 0.8 : 7.8 

Non-Road Mobile Source Subtotal 70.5 : 65.3 

· 

165.5 : 129.7 

165.5 : 129.7 

376.8 : 478.6 

53.0 : 694.0 

· 429.8 : 1172.6 

61.0 : 61.3 

122.9 : 1092 

122.9 : 109.2 

338.5 : 471.8 

53.0 : 694.0 

391.5 : 1165.8 

On-Road Mobile Sources 

On-Road Mobile (inclUding vehicle refueling) 

On-Road Mobile Subtotal 

Anthropogenic Total 

Bioaenic Total 

Anthropoaenic & Bioaenic Total 

14 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.4.2. Discussion of 2010 Base Case CAMx Modeling Results 

Currently, Colorado's highest emissions density is along the Front Range. As shown in 

Figure 5 Photochemical Modeling done for the DMAINFR SIP process shows that the 

highest 201 0 ozone design values along the foothills west of Denver and Fort Collins. 

Ozone concentrations decrease rapidly to the east of Denver. The maximum projected 20 I0 

base case 8-hour ozone Design Value of 84 ppb occurs at both the Rocky Flats North and 

Fort Collins West monitoring sites. As this value is 84 ppb or lower, the 2010 base case 

modeling results pass the EPA modeled attainment demonstration test. Although the EPA 

8-hour ozone projection procedure is to truncate the final projected DVF for comparisons 

with the NAAQS, the projected 2010 base case future years design value is 84.9 ppb 

(Morris, et aI, 2008a). White (unshaded) areas in Figure 5 have future design value of less 

than 63.8 ppb. 

Figure 5. Projected 2010 8-hour ozone Design Values (DVF) 

Figure 6 presents the ozone source apportionment results, including the boundary 

conditions. The boundary conditions (BCs) show the contribution from sources outside the 

15
 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

12 kIn domain (see Figure 4) for a given high ozone day (results vary by day). On this day, 

of the 76.1 ppb of ozone estimated at the monitor, approximately 48 ppb was transported 

into the 12 kIn domain and approximately 8 ppb was attributed to sources in the sevencounty Denver Metro area (Morris, et aI, 2008a) while the rest was from other counties in 

Colorado or from other states. This suggests that, on this day, ozone was generated 

primarily by global/continental scale "background" and local sources of emissions in the 

Denver Metro area. Transport from nearby states was relatively small. 

,-. 

.a 

0.. 

0 

>::: 

0 

u 

I1J 

>::: 

0 

N 

0 

72 

64 

56 

48 

40 

32 

24 

16 

8 

0 

run16c.osaUy2010.1204 

060729 (2006210) 

Metric-03M Average >= 70.0 PPB 

Total Ozone 76.1 (ppb) - Receptor rfno 

~-~----_.~----------~

§ 

+ 

CI 

'" + 

IC 

• BC 

• EGU 

• NonEGU • Area iilII OiICas 

• Nonroad 

Motor Veh. 

• BioFire 

23 o 0 + + U u 8 

IiO + + til Z t: 

OSAT Source Regi6hs 

o 

(.) 

z 

Figure 6. Rocky Flats North source apportionment for 29 July including boundary conditions. 

Conclusions from ozone source apportionment results (Morris, et aI, 2008a) vary by day 

and by location. However, several overall trends emerged, namely: 

•	 Regional ozone transport into the 12 km domain is the largest contributor, often 

accounting for more than two-thirds of the total ozone; 

•	 At the Denver Metropolitan monitors the largest contributors are Denver
 

Metropolitan metro area motor vehicle and non-road sources;
 

•	 At the Fort Collins and Greeley monitors, the largest contributors tend to be 

Larimer and Weld County motor vehicles, non-road sources and oil and gas 

sources, and Denver Metropolitan sources; 

•	 The majority ofthe ozone formed is attributable to anthropogenic NOx emissions. 

16
 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment I Air Pollution Control Division 

In interpreting these results, it is important to keep in mind that the source apportionment 

results are based on the Denver SIP 2006 modeling episode and are meteorologically 

dependent For instance, the source apportionment modeling in support of the Denver 

Early Action Compact using a 2002 ozone episode (Morris, et aI, 2004a) showed more 

impact from sources in northern Colorado in the Denver Metropolitan area. 

Other ozone transport studies also confirm that Denver is impacted by ozone from areas 

well outside of Colorado. A report sponsored by the Western States Air Resources Council 

(WESTAR) indicates that, when ozone is greater than 85 ppb in Denver, natural 

background accounts for 37.5% ofthe total concentration, transported anthropogenic 

generated ozone is 37.5%, and the local anthropogenic ozone contribution is about 25% 

(MacDonald, et. aI, 2006). 

A common theme at all ozone monitors is that a majority of the peak 8-hour ozone is due to 

ozone transport from sources outside of Colorado and outside the 12km domain boundary. 

Source apportionment modeling indicates that transport into the region accounts for 

approximately 60-75% of the ozone formation in the DMAINFR. This indicates that the 

DMAINFR is more of a receptor of ozone and ozone precursors rather than a producer of 

ozone and precursors that transports ozone to areas outside of the Front Range. While the 

modeling suggests that the transport of ozone andlor ozone precursors is a significant issue 

in the west, the magnitude of ozone transport from Colorado to other states is too low to 

significantly contribute to nonattainment in, or interfere with maintenance by, any other 

state with respect to the 0.08 ppm ozone NAAQS. 

17
 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(1) • Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.5.	 Denver Metro Area/North Front Range Ozone Nonattainment 

Area Contribution to Downwind Locations 

As part of the Denver EAC, source apportionment modeling was conducted to evaluate the 

spatial extent of the 8-hour ozone impacts due to emissions from various source regions in 

Colorado. A similar analysis was not done as part of the DMA/NFR ozone SIP analysis, 

however, a similar conclusion would be expected. The conclusion is that ozone formed 

specifically from sources in the DMA/NFR nonattainment area decreases rapidly in 

concentration over the eastern plains of Colorado. Therefore, the photochemical modeling 

that was done for both the DMA/NFR ozone SIP and the Denver EAC suggest that ozone 

and/or ozone precursors from the Front Range do not contribute significantly to downwind 

monitors in other states. 

Figure 7 displays the spatial extent of the 8-hour ozone concentrations that occurred 

between lOam and 6pm local time (the time when the daily maximum 8-hour ozone 

typically occur) on June 27,2002 through July 1,2002 due to all emissions (anthropogenic 

and biogenic) from the DMA. As shown in Figure 7, which represents a high ozone 

episode in Denver, the DMA can contribute approximately 10 ppb of ozone at the eastern 

border of Colorado. However, the concentration gradient falls off quickly and emissions 

from the DMA are not expected to be a significant contributor to any ozone nonattaihment 

area downwind of the Front Range. Weld, Elbert, Morgan, Larimer, El Paso and other 

counties contribute even less ozone to the Colorado border states with a maximum 

contribution of 5-10 ppb. 

18
 

State of Colorado Implementation PLan to Meet the Requirements of
 

Clean Air Act Section lID (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment! Air Pollution Control Division 

ContJ1butions fa 8-hr Ozone Contributions to 8-hr Ozone 

#1 0 .. Dft:nv~r ~I'Qp()Ul4lnATe. trom D~r",e,. Mll'tropolitilfl AA~

CAlAx "".01 2OO1·cntlQ.al.3grd CAtot< 'I'I.lU 1OOI-1:nlJ<l.~.:lgrd

20.000 00 --_.• 

15.000 15.000 

10.000 10.000 

So,OOO 

0.000 I """""-~.. > 0.000 rr'o ppa ""n< V20~ 10;00:00 June 28.2002 10:00100 Min O.«jlh1[lIoIl.np....· IS.~fIl' 01(17.371 l.tIn O.OS6at(I.'~M"', 21.(1:JIIII(3:l27) 

Contributions to 8-hr Ozone Conldbutionll to 8-h. Ozone 

I 1).000 

10.000 

s.ooo 

OJlOO I PP8 

Contl'ibutions to 8-hr Ozonehom l}el1ver Mrtropolihn ArY-ii 

CAMII(y,q.A)~ ~l-cnt"'.a:2.3grd

..,......., r---,----.,-----Tl
 

15.000 

HJ.OOO 

'.OQO 

..
 July 1.2002 10iJO:110
 

",. Min- OJlOO at 1.Sll1 M.... :18.21\ 0«:1<1.33)
 

Figure 7: Spatial extent of the 8-hour ozone concentrations that occurred between lOam and 6pm local time 

on June 27,2002 through July 1,2002 

/9
 

State ofColorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

1.6. Section 110(a)(2)(D)(i)(l) - Ozone Transport Conclusions 

With respect to the 0.08 ppm ozone NAAQS, emission control programs in the Colorado 

SIP are expected to adequately protect downwind neighboring states from interstate 

transport of ozone, per Clean Air Act (CAA) Section 11 0(a)(2)(D)(i)(I). 

Ambient monitoring data in and around Colorado support the assertion that Colorado does 

not contribute significantly to nonattainment in, or interfere with maintenance by, any other 

state with respect to the 1997 8-hour ozone NAAQS of 0.08 ppm. Colorado is unlikely to 

interfere with maintenance of the 8-hour ozone standard in downwind or potentially 

doWnwind states is supported by monitoring data collected in neighboring states (see Table 

4) and the results of photochemical modeling analysis as discussed in Section 1.4.2 and 1.5. 

Specifically: 

1. Ozone concentrations measured at Kansas, Nebraska, and Wyoming monitors closest 

to Colorado are significantly below the nonattainment threshold. In addition, the 

results of the photochemical analysis discussed in the sections noted above show that 

the ozone values in the easternmost Colorado counties are sufficiently low to make it 

unlikely for ozone transport from Colorado to interfere with maintenance of the 1997 

NAAQS in downwind state. 

2. A review of recent ozone observations from the EPA AQS database shows that, with 

the exception of a single monitor in Jefferson County, Colorado (i.e., Rocky Flats 

North), all monitoring sites in Colorado and adjacent states that are likely to be 

impacted by Colorado demonstrated attainment of the 0.08 ppm 8-hour ozone NAAQS 

for the three year period of 2005-2007. Since ozone monitors in adjacent states comply 

with the 0.08 ppm NAAQS, it logically follows that Colorado does not cause or 

contribute to monitored violations or interfere with maintenance of the 0.08 ppm ozone 

NAAQS in any other state. 

3. For Rocky Flats North, which is the only monitor in Colorado that has levels above 

the 0.08 ppm ozone NAAQS, the preliminary three-year average (2006-2008) fourth 

high value is 0.086 parts per million (ppm), which is only slightly above the 0.08 ppm 

ozone NAAQS. . 

4. Observations from current networks show that the highest ozone levels in Colorado 

occur along the Colorado Front Range and not in other areas of Colorado. 

5.0zone monitoring data from the surrounding states that are most likely to be 

impacted by Colorado (i.e., Nebraska, Kansas, New Mexico, Wyoming, and Utah) 

show that none of the monitors exceed the 0.08 ppm 8-hour ozone standard. Since the 

areas represented by these monitors are in monitored attainment, it is higWy unlikely 

that existing 0.08 ppm ozone nonattainment areas beyond these areas are significantly 

affected by emissions from Colorado. The nearest 0.08 ppm ozone nonattainment areas 

to DMAlNFR Nonattainment Area are: 

a. Phoenix, Arizona (Basic Area for 8-Hour ozone) at a distance of 586 miles; 

20 

State of Colorado Implementation Plan to Meet the Requirements of 

Clean Air Act Section 110 (aX2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone 
Colorado Department of Public Health and Environment I Air Pollution Control Division 

b.	 Las Vegas, Nevada (Basic Area for 8-hour ozone) at a distance of 628 

miles; 

c.	 Dallas, Texas (Moderate 8-hour ozone nonattainment area) at a distance of 

663 miles; and 

d.	 St. Louis, Missouri (Moderate 8-hour ozone nonattainment area) at a 

distance of 796 miles. 

Photochemical modeling and other technical analyses performed for the Denver Early 

Action Compact (EAC) and the Denver Metro Area and North Front Range (DMA/NFR) 

8-hour Ozone SIP support the assertion that Colorado does not contribute significantly to 

nonattainment in, or interfere with maintenance by, any other state with respect to the 0.08 

ppm ozone NAAQS. Specifically: 

1.	 The Denver 8-hour Ozone SIP photochemical modeling for 2010 and the associated 

weight of evidence analyses suggest that the DMA/NFR nonattainment area and 

downwind areas already comply or will comply with the 0.08 ppm ozone NAAQS 

by2010. 

2.	 Photochemical modeling shows that elevated ozone concentration levels generated 

from local emissions decrease rapidly with distance. 

3.	 A review of photochemical modeling performed for both the DMA/NFR Ozone SIP 

and the Denver EAC, including boundary condition analyses, suggests that the 

magnitude of ozone transport from Colorado to other states is too low to 

significantly contribute to nonattainment in, or interfere with maintenance by, any 

other state with respect to the 0.08 ppm ozone NAAQS. 

In summary, a review of monitoring data, photochemical modeling, and weight of evidence 

analyses generated for the DMA/NFR SIP process suggests that the transport of ozone and 

ozone precursors from Colorado does not cause or significantly contribute to nonattainment in, 

or interfere with maintenance by, any other state with respect to the 0.08 ppm 8-hour ozone 

NAAQS. This analysis does not address ozone transport for the revised 0.075 ppm 8-Hour 

Ozone NAAQS. 

21
 

State of Colorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(l) • Interstate Transport Regarding 8-Hour Ozone
 
Colorado Department of Public Health and Environment / Air Pollution Control Division 

2. REFERENCES 

Coats, C.J. Jr. "High-performance algorithms in the Sparse Matrix Operator Kernel Emissions 

(SMOKE) modeling system." Proc. Ninth AMS Joint Conference on Applications ofAir 

Pollution Meteorology with A WMA. Amer. Meteor. Soc., Atlanta, GA, 584-588. 1996. 

ENVIRON. User's Guide - Comprehensive Air Quality Model with Extensions - Version 

4.40. ENVIRON International Corporation, Novato, CA http://www.carnx.com. February 

2008. 

Consolidated 

Loomis, C., 1. 

Community 

Wilkinson, 

Emissions 

J. Haasbeek, 

Processing 

A. Pollack 

Tool, 

and 

An 

M. 

Open-Source 

Jansen. 2005. 

Tool 

"ConCEPTfor the Emissions 

Modeling Community." Presented at the 14th International Emission Inventory Conference 

"Transforming Emission Inventories - Meeting Future Challenges Today", Las Vegas, 

Nevada, April 11- 14. <http://www.epa.gov/ttn/chief/conference/ei14/session l1/loomis.pdf> 

MacDonald, C., Miller, D., Raffuse, S., 2006. Regional and Local Contributions to Peak Local 

Ozone Concentrations in Six Western Cities. Sonoma, Technology, Inc., Petaluma, CA. 

Prepared for WESTAR Council of Governments.. May 16 

Morris R., E. Tai, Tanarit Sakulyanontvittaya, D. McNally and C. Loomis. 2008a. 2010 Ozone 

Projectionsfor the 2010 Base Case and 2010 Sensitivity Tests and 2010 Ozone Source 

Apportionment Modelingfor the Denver 8-Hour Ozone State Implementation Plan. ENVIRON 

International Corporation, Novato, California. Prepared for Denver Regional Air Quality 

Council (RAQC), Denver, Colorado. September 8. 

Morris R., E. Tai, Tanarit Sakulyanontvittaya, D. McNally and C. Loomis. 2008b. 2010 Ozone 

Attainment Demonstration Modelingfor the Denver 8-Hour Ozone State Implementation Plan 

Control Strategy. ENVIRON International Corporation, Novato, California. Prepared for 

Denver Regional Air Quality Council (RAQC), Denver, Colorado. September 22. 

Morris, R.E., G.E. Mansell, E. Tai, D.A. McNally and T.W. Tesche. 2004a. Air Quality
 

Modeling Analysis for the Denver Early Action Compact: Ozone Source Apportionment
 

Modelingfor the Denver EAC. Prepared for the Colorado Department of Health and
 

Environment and Denver Regional Air Quality Council, Denver, Colorado. Prepared by
 

ENVIRON International Corporation, Novato, CA. May 31 ..
 

Utah Air Quality Board, 8-Hour Ozone Maintenance Provisionfor Salt Lake and Davis
 

Counties, January 3, 2007.
 

22
 

State ofColorado Implementation Plan to Meet the Requirements of
 

Clean Air Act Section 110 (a)(2)(D)(i)(I) - Interstate Transport Regarding 8-Hour Ozone
 
Final Adoption Notice
 
STATE OF COLORA.DO
 

Bill Ritter, Jr., Governor
 

James B. Martin, Executive Director
 

Dedicated to protecting and improving the health and environment of the people of Colorado 

4300 Cherry Creek Dr. S. Laboratory Services Division
 

Denver, Colorado 80246-1530 8100 Lowry Blvd.
 

Phone (303) 692-2000 Denver, Colorado 80230-6928
 

TOO Line (303) 691-7700 (303) 692-3090
 Colorado Department Located in Glendale, Colorado of Public Health 

http://www.cdphe.state.co.us and Environment 

NOTICE OF FINAL ADOPTION 

PURSUANT to the provisions of sections 25-7-105,25-7-105(12),25-7-114 through 25-7-114.7, 25-7­

106,25-7-119 and 25-7-132 C.R.S. of the Colorado Pollution Prevention and Control Act. 

NOTICE IS HEREBY GIVEN that after a public rulemaking hearing December 12,2008, and in 

compliance with the requirements of sections 25-7-105, 25-7-110, and 25-7-110.5, C.R.S., the Colorado 

Air Quality Control Commission made revisions to: 

Interstate Air Pollutant Transport State Implementation Plan 

The Commission adopted revisions to an ozone action plan for the Denver Metropolitan and North Front 

Range 8-hour ozone nonattainment area. The ozone action plan modified the provisions of the Interstate 

Air Pollutant Transport State Implementation Plan element adopted by the Commission in February 2007, 

by noting that the proposed maintenance plan would prevent the Colorado Front Range from contributing 

significantly to ozone non-attainment or interfere with long-term maintenance ofthe national ozone 

standard in any other state. 

This action was submitted to the Secretary of State's Office within 20 days after adoption for publication 

in the Colorado Register, pursuant to 24-4-103(5) and (11)(d), C.R.S., and will become effective January 

30,2009. 

Additionally, pursuant to 24-4-103(8)(d), C.R.S., within 20 days after the date of the Attorney General's 

Opinion, this action will be submitted to the Office of Legislative Legal Services for review. 
Opinion ofthe Attorney General 

Not Applicable 
Regulation as Published in the CCR 

(this is the version that is published by Lexis Nexis) 

Not Applicable